Showing papers in "Journal of Food Process Engineering in 2016"

Ultrasound as a Pretreatment Method to Improve Drying Kinetics and Sensory Properties of Dried Apple

Abstract: The effect of ultrasound pretreatment on drying kinetics and physical properties as color and rehydration rate of dried apple slices was investigated. Apple samples var. Idared were submitted to ultrasonic treatment using 21 and 35 kHz for 30 min in an ultrasound bath securing sound intensity of 3 and 4 W/cm2, respectively. After pretreatment, the material was dried in a convective oven at 70C and at an air velocity of 2 m/s. The sonication reduced drying time by 13–17% in comparison with the untreated sample. Ultrasound treatment changed the color of apples tissue by decreasing the value of a* parameter and increasing the dried material lightness, chromaticity and the value of b* coefficient. Moreover, obtained results showed that there was a significant effect of pretreatment on rehydration properties as compared with untreated apple tissue. Practical Applications The most energy-consuming processes existing in the food technologies are the processes based on heat and/or mass transfer, for instance drying. Thus, a lot of attention is paid by researchers to conserve the energy and minimally change the physicochemical properties of food, which shape its quality. Additionally, increasing growth of consumers' expectations and their nutritional knowledge stimulate to seek some new solutions even more. Aforementioned is a reason why nonthermal technologies as ultrasound seem to be the one of the most interesting propositions.

Optimization of Foaming Properties and Foam Mat Drying of Muskmelon Using Soy Protein

Abstract: The effect of concentration of soy protein isolate (SPI), carboxymethyl cellulose (CMC) and whipping time on foaming properties of muskmelon pulp was investigated. Box–Behnken design of experiments was used to optimize the foaming process. The optimum conditions for foaming process were found to be 8.71% of SPI concentration, 0.54% of CMC concentration and a whipping time of 5.7 min. The muskmelon foamed at optimum conditions was dried using hot air dryer at 50, 60 and 70C. The drying rate was found to be high at 70C. The effective moisture diffusivity of foamed muskmelon pulp was determined and compared with the unfoamed muskmelon pulp. The powder properties such as density, color, water absorption index, solubility index, Hausner ratio and Carr index were also determined for muskmelon. Practical Applications Fruit juice powders have been considered as economically viable over their liquid counterparts because it has improved shelf life, low volume/weight, less space volume required for storage, simpler handling and transportation. Among various drying processes, the foam mat drying process has be successfully used for the production of fruit powders because of rapid drying at lower temperature, retention of high nutrition, easy reconstitution characteristics and its cost-effectiveness. This foam mat drying process is much cheaper than freeze and spray drying for the production of fruit powders. The muskmelon powders find application in snacks, beverages, ice creams and bakery industries for production of many food products, and it is also used as a starter for the preparation of instant foods and pastes.

Effect of Vibration on the Quality of Strawberry Fruits Caused by Simulated Transport

Abstract: Mechanical damage of agricultural products is one of the main problems in the harvest and postharvest chain due to the large economic loss that the shelf life reduction could generate. Measurements of change in the chemical components of highly perishable products and microbial growth under different static and dynamic loads is the first step in the development of intelligent logistic units that could help in predicting the residual shelf life in order to minimize losses along the supply chain. In our research, the effects of vibration along the supply chain of a case study were analyzed on strawberry (Fragaria × ananassa) and woodland strawberry (Fragaria vesca) in terms of microbiological and quality assessment. Fruits were subjected to vibration in a temperature-controlled environment, simulating the transport conditions. Microbiological and quality analyses were conducted in three different positions along the column of the crates. The results were compared with the nonvibrated strawberries stored in the same environmental conditions along the whole cold chain, showing that vibrations cause a significant decrease in the qualitative characteristics of both fruits. Practical Applications The practical application obtainable from our research is the development of ad hoc economically affordable sensors based on the volatile organic compounds (VOCs) emitted by the microorganisms showing the most rapid increase. The measurement of the VOCs of the dominant microorganisms could be implemented in a smart logistic unit as it provides information on the microbial evolution in real time. The research proposed configures as a first step to achieve such objective, and toward the development of a supply chain monitoring and control infrastructure relaying on the correlation of vibration phenomena with the VOCs originated by the microbiological activity. The methodology consists of measuring the effects of vibration along a reference supply chain in terms of microbiological and quality assessment, with the aim of extrapolating a mathematical correlation that can further be generalized into a replicable model.

Physical Stability and Antimicrobial Activity of Encapsulated Cinnamaldehyde by Self-Emulsifying Nanoemulsion

Abstract: In the present study, natural cinnamaldehyde was encapsulated in self-emulsifying emulsion systems. After optimization, the stability of encapsulated cinnamaldehyde was evaluated by dynamic light-scattering and electronic nose. The antimicrobial activity of cinnamaldehyde was investigated by minimum inhibition concentration and time-kill assay. The results showed that pure cinnamaldehyde as oil phase could not form stable emulsion under different oil-to-surfactant ratio. Stable cinnamaldehyde nanoemulsions were achieved with the addition of medium-chain triglyceride. With the exception of temperature, the obtained nanoemulsions were stable against pH and NaCl. Phase separation was observed after 12 days of storage under 37C. Encapsulation efficiency of cinnamaldehyde in nanoemulsions was maintained around 80% within 1 week. Radar plots from electronic nose indicated that encapsulation could slow the release of cinnamaldehyde from nanoemulsion. Hence, the antimicrobial activity of cinnamaldehyde encapsulated in nanoemulsion could provide a long-term inhibition on the bacterial growth of Escherichia coli compared with pure cinnamaldehyde. Practical Applications The applications of natural essential oils with their excellent antibacterial activities, such as cinnamon essential oils, as a food additive and green preservative are limited in the food systems, due to their highly instability against environmental conditions including temperature, light, air and others. The emulsification technique has been successfully utilized to overcome this drawback. However, it is known that emulsions with essential oils as oil phase will be highly unstable due to Ostwald ripening. Although the evaluation of the stability and bioactivities of encapsulated essential oil is an important and critical issue during the practical application, hence, studies of the physical properties such as environmental stability, volatility and antibacterial activity can explore the ideal formulation and applications of natural essential oils.

Comparison of Acidic and Enzymatic Pectin Extraction from Passion Fruit Peels and Its Gel Properties

Abstract: The influences of extractor concentration, extraction temperature and time on the yield of pectin and degree of esterification (DE) were investigated by the acidic and enzymatic extraction methods. Citric acid and Celluclast were selected as pectin extractors for environmentally friendly reasons. The peels of yellow passion fruit using the acidic and enzymatic extraction methods gave pectin yield of 7.16 and 7.12%, and DE of 71.02 and 85.45% in the optimized condition of extraction time of 102 min with citric acid concentration of 0.19% (w/w) at 75C and Celluclast concentration of 1.67% (w/w) at 61.11C, respectively. The enzymatic extraction method has greater capability of producing high methoxyl pectin. The morphological features of fruit peel powder and the extracted pectin examined by scanning electron microscopy suggested that the nanostructure of wet passion fruit pectin was dependable on the type of extraction process. The formed pectin gel also has pseudoplastic liquid behavior and its viscosity was greatly affected by sugar. Pectin has been intensively used as natural gelling agent and stabilizer to alter rheological properties in food ingredients by most food processing industries to achieve desired textural quality. Pectin could be recovery from fruit wastes. The conversion of passion fruit peel into pectin offers great scope for utilization. Citric acid and enzymatic extraction methods are effectively used for pectin extraction which may be of interest by pectin industry and consumer with these eco-friendly processing technology with no using harmful chemicals. Furthermore, scientific work of this study such as the optimized condition, morphological features of extracted pectin and pectin gel formation contributes valuable information on pectin, which could be beneficial for pectin industry improving the process quality of pectin as well as process profitability.

Thermal versus Microwave Inactivation Kinetics of Lipase and Lipoxygenase from Wheat Germ

Abstract: The inactivation kinetics of enzymes is an important way to reveal the mechanism of enzyme inactivation by microwaves. In this paper, lipase (LA) and lipoxygenase (LOX) were treated by both microwave irradiation and conventional heating. A temperature-controlled water bath was used for conventional heating, and a microwave monomode reactor with a simultaneous cooling and precise temperature control system was used for microwave irradiation. The results showed that the effects of both microwave irradiation and conventional heating on enzyme inactivation were enhanced as system temperature increased; LOX was more sensitive to heat than LA. Therefore, compared with conventional heating, microwave irradiation shows no significant differences in inactivating LA or LOX in aqueous solution, and the thermal effect of microwave irradiation is the main cause of enzyme inactivation. Practical Applications Wheat germ has a short shelf life because of the high activity of endogenous enzymes. Two relevant endogenous enzymes are involved in the degradation of nutrients, lipase (LA) and lipoxygenase (LOX); therefore, the inactivation of LA and LOX is an essential prerequisite for long-term storage of wheat germ. Microwave irradiation treatment (MIT) has long been applied to the inactivation of enzymes and has several advantages such as having a minimal effect on food product quality and providing rapid and uniform heating. However, the mechanism of enzyme inactivation by microwaves is still controversial. In this study, wheat germ endogenous enzymes were treated by MIT and conventional heat treatment. Based on residual enzyme activities and first-order rate of inactivation kinetics, the mechanism of microwave inactivation was demonstrated, offering a theoretical basis for the future application of this technique in grain stabilization.

Preparation and Characterization of Chitosan Nanoparticles-Loaded Fish Gelatin-Based Edible Films

Abstract: Bio-based nanocomposite films were obtained from fish gelatin (FG) and different amounts of chitosan nanoparticles (CSNPs) (0, 2, 6 and 8% w/w) with diameters ranging from 40 to 80 nm. The influence of nanoparticles on the surface morphology, physicochemical properties, crystalline structure and thermal stability of FG was investigated. The surface morphology assay showed a considerable increase in roughness parameters by incorporating the nanoparticles in FG matrix. Contact angle measurements ranged from about 45C to 60–97C as filler concentration increased, indicating that reinforced films had higher superficial hydrophobicity than neat FG ones. The X-ray diffraction results also suggested a higher crystallinity in FG matrix due to CSNPs nucleating effect. The glass transition of the nanocomposites was shifted to lower temperatures with respect to the pure FG. Thermal stability tended to increase in accordance with CSNPs content, in which the highest shift of degradation temperature was observed at 6% (w/w) loading content. Practical Applications In recent years, bio-based polymers have attracted more and more attention due to growing environmental concern and decreasing reserve of fossil fuel. This recent evolution encourages researchers and industries to develop novel materials labeled as “environment friendly.” This study investigates the preparation and characterization of eco-friendly fish gelatin-based composite reinforced with chitosan nanoparticles, as a substitution of plastic packaging materials with the goal of decreasing environmental pollution.

Pulsed Electric Field-Assisted Enzymatic Extraction of Protein from Abalone (Haliotis Discus Hannai Ino) Viscera

Abstract: Different conditions of pulsed electric field (PEF) intensity strength, treatment time and the ratio of material to solvent of PEF-assisted enzymatic extraction of the abalone viscera protein (AVP) were studied in the article. Optimal PEF extraction conditions were achieved (PEF intensity strength of 20 kV/cm, treatment time of 600 μs and the ratio of material to solvent of 4:1). Detailed comparison of various properties (degree of hydrolysis, nitrogen yield, hydrolysis rate, function properties) of two AVPs was investigated. Application of PEF-assisted enzymatic extraction resulted in fully hydrolyzed, high AVP product yield and good emulsifying properties of AVP when compared to purely enzymatic extraction; however, the foaming properties and viscosity were reduced. In particular, the increase of solubility (91.54%) and the reduction of viscosity of AVP had a good effect on the improvement of solubility of spices, providing a theoretical basis for the development of abalone condiments. Practical Applications The abalone viscera protein AVP is presently extracted through enzymatic extraction. The disadvantage of this method is incomplete hydrolysis. The AVP obtained by pulsed electric field-assisted enzymatic extraction had good hydrolysis (high solubility) and good properties (low foaming properties, viscosity and high emulsify properties). The process developed in this study could be suitable for abalone manufacturers to utilize the abalone viscera to be developed as seafood seasoning.

Application of Combined Far-Infrared Radiation and Air Convection for Drying of Instant Germinated Brown Rice

Abstract: Shorter drying time and reduced energy consumption for instant germinated brown rice drying were evaluated to ensure that the quality of the final product was not compromised. Energy consumption, moisture content, color, morphology, rehydration, texture and sensory evaluation were determined during drying with a combination of far-infrared radiation and hot air. Far-infrared intensities from 1 to 5 kW/m2 were combined with a 40C temperature and 1 m/s air velocity. Drying rate increased with far-infrared intensity, hence reducing the total drying time. The mathematical model was validated by comparing the simulated results with temperature and moisture content to described the drying behavior of instant germinated brown rice (R2 = 0.999). The total color difference (ΔE) varied from 2.9 to 4.2. Increasing far-infrared intensity decreased hardness, chewiness and gumminess, but increased the rehydration of instant germinated brown rice. The effective moisture diffusivity increased with the far-infrared intensity varying from 0.39 × 10−11 to 3.6 × 10−10 m2/s. The specific energy consumption at 5 kW/m2 far-infrared intensity was 2.90 kWh/kg of water removed, resulting in a 66% energy saving when compared to 1 kW/m2 far-infrared intensity. Practical Applications As an excellent source of nutrients, germinated brown rice has gained more attention than white rice. However, information on instant rice obtained from germinated brown rice is scarce. An alternative technique about instant germinated brown rice preparation was therefore proposed in this work. This study gives a method for the preparation for instant germinated brown rice, which would be a good choice for production of instant germinated brown rice in the industry.

Steady Shear Flow Behavior and Thixotropy of Wheat Starch Gel: Impact of Chemical Modification, Concentration and Saliva Addition

Abstract: The rheological properties of native wheat starch (NWS), cross-linked wheat starch (CLWS) and hydroxypropylated wheat starch (HPWS) gels at two concentrations (8 and 12%) and in the presence and absence of saliva at 37C were investigated. More decrease in viscosity was observed for the HPWS (83.33%) gel samples at simulated mouth conditions (SMCs) compared to the NWS (32.05%) and CLWS (23.88%) gel samples. In the absence of saliva, the Herschel–Bulkley and Sisko models were the best ones to describe viscous flow behavior of all starch gels. The highest thixotropy extent was obtained for the HPWS (1.98–9.26) while no statistically significant difference was observed for that between the NWS and CLWS gel samples (P > 0.05). The first-order stress decay model predicted the closest data in the SMC. The results suggested that chemical modification such as hydroxypropylation and cross-linking can be used to manipulate or modify the rheological behavior of starch in the mouth conditions. Practical Applications Because of many nutritional, technological and textural advantages of starch in food and pharmaceutical systems, it is receiving much more attention. Investigation of the changes in such bioactive carbohydrates in gastrointestinal tract has recently been considered. Study of the rheological parameters is one of the ways to find the influence of each digestion process on the structural properties of starch samples. In this work, steady shear flow behavior and thixotropy of wheat starch gel affected by the type of wheat starch (native, cross-linked and hydroxypropylated), concentration and saliva addition (SMCs) were studied. Investigation of rheological properties in a SMC allows a better understanding of food structure in the mastication condition, which can be used to develop a food product with special mouthfeel or for special consumers like people with dysphagia.

Combining ultrasound with mild alkaline solutions as an effective pretreatment to boost the release of sugar trapped in sugarcane bagasse for bioethanol production.

Abstract: The aim of this work was to develop and optimize process parameters in ultrasound and sono-assisted alkaline pretreatment of sugarcane bagasse prior to hydrolysis and bioethanol fermentation processes. Following the optimization of ultrasound time and temperature, the influence of concentration of NaOH solution was examined. The optimal condition in ultrasound pretreatment (35 kHz) was achieved at 5 min and 65C. Ultrasound pretreatment of bagasse prior to hydrolysis step resulted in increased sugar concentration from 3.62 g/L (control, 25C) to 5.78 g/L (65C, 5 min). The micromorphology and cellulose crystallinity for native and pretreated bagasse were investigated by scanning electron microscopy and X-ray diffraction, respectively. The maximum glucan conversion and bioethanol production of 50% and 0.38 g/g glucose were achieved following sono-assisted alkaline pretreatment (3% NaOH concentration), respectively. The findings indicate that sono-assisted alkaline pretreated bagasse can be used as a potential feedstock in bioethanol production. Practical Applications Current bioethanol production uses food crops such as sugarcane and maize. Large amounts of sugar molecules are present in the lignocellulose of plant material and current research aims to “unlock” the fermentable sugars in agricultural or forestry wastes and residues. The objective of the present research was to find an optimum pretreatment method by combining ultrasound with various concentrations of mild alkaline solution in order to make use of a greater proportion of lignocellulose materials from the sugarcane bagasse for bioethanol production. The development of an efficient pretreatment to increase the cellulose digestibility and fermentability potential of biomass may be of interest in bioethanol industries.

Quality Characteristics of Wheat Germ Oil Obtained by Innovative Subcritical Butane Experimental Equipment

Abstract: Subcritical butane extraction (SBE) was used to extract oil from wheat germ and was compared with conventional n-hexane extraction (CHE) and supercritical CO2 extraction (SC-CO2E) methods. By analyzing the extraction yield, composition of fatty acids and characteristic functional contents such as VE, phytosterols and phospholipids in wheat germ oil (WGO), the selective extraction characteristics of subcritical butane were evaluated. The results indicated that compared with SC-CO2E and CHE, SBE had no significant difference in oil yield, fatty acid compositions, acid value and peroxide value of WGO. However, the content of phytosterols in the oil extracted by SBE (2,326 mg/100 g) was higher than that extracted by CHE (921 mg/100 g) or SC-CO2E (1,381 mg/100 g). The VE content of WGO extracted by SBE (359 mg/100 g) was equivalent to that extracted by CHE (357 mg/100 g) and slightly less than that extracted by SC-CO2E (374 mg/100 g). And the content of phospholipids in WGO extracted by SBE (12.41 mg/g) was lower than that extracted by CHE (17.78 mg/g). In conclusion, SBE was able to retain the bioactive compounds in WGO when compared with CHE. Practical Applications Wheat germ oil is a type of functional oil enriched with bioactive compounds that have great latent capacity for further exploitation. However, conventional extraction methods of edible oil lead to oil oxidation and degradation or loss of bioactive components after desolvation and refinement (Pradhan et al. 2010). In addition, due to the shortcomings of supercritical CO2 extraction technology such as costly equipment investment, low productivity and high cost of production, subcritical fluid extraction technology can be applied to industrial production owing to its use of low pressure and room temperature for extraction. The present study demonstrates that subcritical butane has better extracting power for bioactive compounds in wheat germ oil than conventional n-hexane. Choosing subcritical butane extraction technology can help the fats and oils industry to improve the quality of high value-added oil while lowering production costs.

Infrared Radiation and Microwave Vacuum Combined Drying Kinetics and Quality of Raspberry

Abstract: Infrared radiation and microwave vacuum combined drying (IR-MVD) kinetics and quality of raspberries under different microwave powers (400, 600, 800 W) and vacuum pressures (45, 65, 85 kPa) were investigated. Drying processes were found to be well fitted with Henderson and Pabis model for infrared radiation drying (IRD) and Midilli model for microwave vacuum drying (MVD). Drying time was reduced and moisture effective diffusivity (Deff) was promoted with the increase of microwave power. In terms of vacuum pressure, the most rapid moisture diffusion was noted at 65 kPa. IR-MVD led to brighter products but caused decreases in redness values. The highest a* value (11.33), lowest ΔE value (12.66) and largest h° value (9.01) were noted at the condition of 600 W and 85 kPa. No significant difference was found between crispness values for different IR-MVD conditions. Good rehydration property was obtained under the strongest microwave power and the highest vacuum pressure. Additionally, anthocyanin losses happened and antioxidant activity declined during dehydration. The highest anthocyanin retention (66.24%) was obtained at the condition of 600 W and 65 kPa. The maximum retention of the antioxidant capacity determined by ABTS (2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)), DPPH (1,1-diphenyl-2-picrylhydrazyl) and FRAP (ferric reducing ability of plasma) were 72.12, 75.03 and 55.19%, respectively, at the vacuum pressure of 85 kPa and microwave power of 600 W. By comparison, the time IR-MVD used was only 55.56% of IRD; moreover, raspberries dried by IR-MVD showed 25.63% higher rehydration ratio, 2.4 times higher crispness value, 17.55% higher anthocyanin retention and 21.21% higher DPPH radical-scavenging activity than IRD. Practical Applications Fresh raspberries, with juicy and soft texture, are highly perishable fruits and are frequently dehydrated so that they are available to consumers throughout the year. Dehydrated raspberries are also desirable as ingredients in dairy and bakery products. Infrared radiation and microwave vacuum combined drying (IR-MVD) was adopted for raspberry dehydration in order to achieve dehydrated products with high drying efficiency and good quality. The effects of the drying parameters, including microwave powers and vacuum pressures, on the drying characteristics and quality of raspberries were studied. The results showed that drying under high microwave power increased drying rate. High vacuum pressure promoted better product color and rehydration property as well as anthocyanin preservation and antioxidant activity. IR-MVD was proved to improve the rehydration properties, anthocyanin retention and antioxidant capacity of products in comparison with infrared radiation drying alone. Therefore, IR-MVD is a promising method to promote drying efficiency and protect the quality of raspberries. The results of this study contribute to the technological application of IR-MVD for raspberry dehydration and preservation.

Extraction of Kiwifruit Seed (Actinidia Deliciosa) Oil Using Compressed Propane

Abstract: This study reports the extraction of kiwifruit seed oil using compressed propane as solvent and its modeling based on the Brunauer–ETmmett–Teller theory of adsorption. Temperature and pressure were the variables investigated on the kinetics of extraction. The overall extraction yields were compared with the Soxhlet extraction with n-hexane. Most of extraction conditions using compressed propane have presented high extraction rates and overall extraction yield of 31.7 ± 1.4%. The kinetic model used showed to be able and very reliable to correlate the different conditions of extraction with compressed propane. Furthermore, the alternative extraction technique investigated in this work was found to be suitable for the oil extraction from kiwifruit seeds after short times of extraction. Practical Applications Compressed propane extraction is an environment-friendly technology that can be efficiently used in oilseed extractions. A product that is free of residual solvent and without degradation of thermolabile compounds highlights the use of compressed propane as solvent for applications in food, cosmetic and pharmaceutical industries. The kiwifruit seed oil, which is predominately constituted by α-linolenic acid (ALA), was efficiently extracted using compressed propane with a maximum extraction yield in a short time of extraction. The mathematical model applied to represent the kinetics of extraction is based on three parameters with physical meaning and it may be easily and reliably used in modeling, design, simulation and optimization, as well as in the scale-up of this extraction process.

Optimization of Cryogenic Grinding Process for Cassia (Cinnamomum loureirii Nees L.)

Abstract: The cryogenic grinding conditions for cassia powder were optimized with four independent variables, viz., feed rate (2–10 kg/h), grinding temperature (−130 to 30C), peripheral speed (7.77–18.13 m/s) and moisture content (6–14% d.b.) using central composite design (CCD) and response surface methodology (RSM). The optimization was targeted to obtain the cassia powder with a lower particle size (μm), together with a minimum color difference (ΔE*) and specific energy consumption values (kJ/kg), while retaining maximum volatile oil content (mL/100 g) in the sample. The numerical optimization suggested that the cryo-grinding of the sample of 9.1% moisture content with the feed rate of 2 kg/h would be the optimum (desirability value of 0.91) at −97C of grinding temperature and 10.5 m/s peripheral speed, respectively. The optimized condition was validated further at the nearest possible condition within the domain. At the optimized cryo-grinding condition, the final particle size of 60 μm containing 2.9 mL/100 g volatile oil and the specific energy consumption of 31.3 kJ/kg was obtained. In addition, the corresponding color difference in the optimized sample was minimal (ΔE* < 3). Practical Applications The results of this study will enable the spice industry to apply the cryogenic grinding process specifically for cassia powder. The optimized condition obtained from this study is capable of producing the cassia powder with desirable particle size together with a minimal loss in its characteristic flavor.

L. plantarum ATCC 8014 Entrapment with Prebiotics and Lucerne Green Juice and Their Behavior in Simulated Gastrointestinal Conditions

Abstract: Lactobacillus plantarum ATCC 8014 was separately encapsulated with pectin and inulin as prebiotics, and lucerne green juice in alginate-coated chitosan microcapsules. Further, they were tested for the efficiency of improving the viability compared to free cells under in vitro acidic conditions. Results indicated significant improvement (P < 0.05) in survival of co-encapsulated cells when exposed to acidic (pH 1.5) and bile (4.5% bile salts) conditions. The encapsulated cells showed about 88.95% survivability in simulated gastric environment, while the samples where the prebiotics and lucerne green juice were used showed about 90.5% of survivability in the same conditions. Moreover, in these samples, the number of viable probiotic cells did not significantly decrease after the first 30 min in simulated gastric juice, but even more, a constantly increase was observed until the end of the 120 min in the same environment. The great potential of lucerne green juice is underlined. Practical Applications The probiotic cells are susceptible to loss of viability and death during processing and storage of food and during their passage through gastrointestinal tract. In order to gain the maximum capacity and optimal activity from these probiotic cells, it is compulsory that they are provided with appropriate conditions for growth and metabolism and at the same time protected from unfriendly environmental conditions to which they are exposed to. Precisely for this reason, in this research, more complex probiotic and prebiotic protective systems have been developed.

Quality of Dough and Bread Prepared with Sea Salt or Sodium Chloride

Abstract: Bread is commonly prepared with salt and, currently, high sodium intake is being regulated because of its negative health effects. Hence, low-sodium sea salt was investigated as a sodium reduction strategy for bread formulation. Various levels of sodium chloride (NaCl) and sea salt were used in a bread formulation. NaCl reduced water absorption of the dough as compared with sea salt. Resistance to extension decreased with the use of sea salt; however, extensibility was higher when compared with bread prepared with NaCl. Loaf volume decreased significantly (P < 0.05) in bread with NaCl. Also, crust color became darker with the increase of sea salt, most likely because of the presence of metal ions (potassium and magnesium) in sea salt. Free sugar content in whole bread, crumb and crust portions were significantly lower (P < 0.05) in breads prepared with sea salt than those prepared with NaCl. Overall, sea salt did not affect bread-making quality, but bread with 0.5% sea salt presented the best quality parameters. These results encourage us to investigate the effects of potassium and magnesium present in sea salt on the structure of gluten proteins, starch behavior and development of color through Maillard reactions. Practical Applications High sodium intake is a major health concern. However, elimination or replacement of sodium has considerable effects on the organoleptic and functional properties of bakery products. Salt is a key ingredient in bread baking and these implications must be taken into consideration when reformulating for sodium reduction. This study evaluates the functional effects of a low-sodium sea salt for use in bread.

Extraction of Minor Compounds (Chlorophylls and Carotenoids) from Yarrow–Rose Hip Mixtures by Traditional versus Green Technique

Abstract: Nowadays, various branches from food industry generate large amount of by-products that are often underutilized, which could have negative environmental impact and increase the price of the raw material as it is not completely utilized in the production. Mixtures of two interesting plants (yarrow and rose hip) with different ratios, obtained as by-products from filter-tea factory, have been extracted with organic solvents and with environmentally friendly technology, supercritical fluid extraction (SFE). In the obtained extracts, quantitative content of minor plant pigments (chlorophylls and carotenoids) was determined and technologies were compared. Moreover, the effect of SFE parameters on yields of chlorophylls and carotenoids was determined. The results showed that SFE could be used as a good alternative for extraction of plant pigments from Achillea millefolium L. and Rosa canina L. mixtures. Besides plant pigments, the obtained extracts were rich in other nonpolar compounds from plant mixtures. Utilization of herbal waste provided value-added products, rich in various health benefit compounds. Practical Applications Currently, there is growing interest for developing economically feasible and environmentally friendly processes for extraction of bioactive compounds from plant material. Moreover, sustainable and relatively cheap raw material should be utilized in the production. Therefore, waste and by-products from the food industry, e.g., plant material from filter-tea factory with small mean particle size, could be used. Traditional technologies used for extraction of chlorophylls and carotenoids are no longer environmentally acceptable and alternative green technologies, such as supercritical fluid extraction, should be considered. This research provides a comparison of green and traditional processes for plant pigment extraction and studies effects of process parameters (pressure and temperature) on yields of the investigated compounds. It also utilizes by-products of two medicinal plants (yarrow and rose hip) as raw material for extraction as herbal dust generated in filter-tea factory could not be used for tea bags filling.

An Artificial Neural Network‐Based Method to Identify Five Classes of Almond According to Visual Features

Abstract: The quality evaluation is one of the key factors that have a major impact on the final price of agricultural products. Nowadays, image processing-based techniques are becoming as an acceptable and widespread in quality evaluation procedures. In this study, we develop a robust method based on image processing and computational intelligence for quality grading and classification of almonds. The images of five classes of almond including normal almond (NA), broken almond (BA), double almond (DA), wrinkled almond (WA) and shell of almond (SA) were acquired by a scanner. For segmentation of images, both H component in HSI color space and Otsu's thresholding method were applied. In the next step, the feature vector, which includes 8 shape features, 45 color features and 162 texture features, was composed. For choosing correlated and superior features among all the 215 extracted features, sensitivity analysis was applied. Principal component analysis method was also used to reduce the dimension of the feature vector. The classification of almonds into different classes was carried out by artificial neural networks (ANNs). Among different ANN structures, the 18-7-7-5 topology was the most optimum classifier. The accuracy of ANN classifier for each class was 98.92% for NA, 99.46% for BA, 98.38% for DA, 98.92% for WA and 100% for SA. The technique can readily be extended for online sorting machines. Practical Applications One of the applications of this method is in the design and fabrication of real-time grading and sorting machines. The biggest advantage of the presented algorithm is its high precision. The developed classifier is able to detect and eject defected almonds (broken, double, wrinkled and shell of almonds) out of a stream of almonds in the sorting process line. Therefore, if the processing time of the method is improved further, it can readily be used in an online sorting machine.

Mathematical Modeling of Ascorbic Acid Thermal Degradation in Orange Juice during Industrial Pasteurizations

Abstract: Orange juice is submitted to thermal treatment to increase its shelf life, which may result in loss of ascorbic acid. This paper uses mathematical models and simulations to reproduce the experimental data of ascorbic acid thermal degradation kinetics. Two different models were considered, and all kinetic parameters were identified using linear regression on the logarithmic curves of experimental data. A quick analytical method based on ultra high-performance liquid chromatography with tandem mass spectrometry was developed to quantify ascorbic acid degradation during the process at three different operating temperatures, allowing the determination of Arrhenius' equations. Ascorbic acid losses were simulated in a tubular industrial pasteurization system by developing an appropriate mathematical modeling, and the residence time presents a higher influence on the process than temperature. In addition, some thermodynamic parameters were evaluated, confirming that the process is not spontaneous but irreversible. Practical Applications The mathematical modeling developed in this research can be used to estimate the ascorbic acid losses during industrial pasteurization processes. The case study of this paper concerns on tubular systems. However, the kinetic parameter estimation and the degradation rate obtained can be used in any industrial situation by an appropriate modeling adaptation, e.g., considering the common plate systems.

Properties of Sugar‐Free Cookies with Xylitol, Sucralose, Acesulfame K and Their Blends

Abstract: Recipes were designed for cookies with sucrose substituted with alternative sweeteners such as xylitol, sucralose and acesulfame K applied either separately or in blends. Rheological and textural properties of resulting doughs were examined. Sensory and textural parameters of cookies were compared with control samples sweetened with sucrose. Viscoelastic properties of the products containing blends of xylitol (X) with acesulfame K (A) (X25A75) and X with sucralose (S) (X50S50) most closely resembled those found for control sample. Doughs sweetened with blends dominated by xylitol had properties best resembling those for control dough. Hardness of baked cookies best resembled that of control when they contained either acesulfame K as the sole additive or a blend of xylitol with sucralose (X50S50). According to the sensory analyses, cookies sweetened with sucrose received the highest score (4.38 points), whereas those sweetened with a blend of xylitol and acesulfame K (X75A25, X50A50) received 3.47 and 3.30 points, respectively. Practical Applications The study offers the sugar-free cookies sweetened either with xylitol or with a blend of xylitol and acesulfame K (X75A25, X50A50), which enjoyed with an appreciation of the sensory panel. The sugar-free cookies elaborated in the presented study could be useful for people suffering from type 2 diabetes as well as for people with obesity. These are mostly diseases of civilization and people suffering from them have limited possibilities of sweet snack consumption. An application of technology, which uses alternative sweeteners, could be an excellent addition to their diet in sweet snacks.

Computational Fluid Dynamics Simulation to Determine Combined Mode to Conserve Energy in Refrigerated Vehicles

Abstract: In this work, to improve the rate at which cool air ventilates the tail of a refrigerated compartment and thereby reduces the temperature difference between the front and rear of the cargo area, we increase the length of an air conduit in the direction of the air outlet of the refrigerating unit. In addition, minimizing the cooling time during transportation reduces energy consumption and improves the economics of cold-chain transport. To address this problem, we created a three-dimensional computational fluid dynamics model of a transport compartment and used potatoes as test cargo. The unsteady shear stress transport κ-ω model was adopted to simulate air flow and heat transfer inside the compartment. The results show that the additional air conduit inside the compartment should significantly improve the spatial uniformity of the temperature inside the cargo area. The results of the simulation are consistent with experiments. Practical Applications Although cold-chain transport must ensure a constant low-temperature environment for perishable foods, more important is the requirement to maintain temperature uniformity in the cargo area. This is the basis by which the quality, safety and shelf life of perishable food are ensured. In this study, we have investigated how to minimize the cooling time during transportation in order to reduce energy consumption and improve the rate at which cool air ventilates the tail of a refrigerated compartment. This research provides reliable theoretical arguments for enhancing temperature uniformity in the cargo enclosure of refrigeration trucks and for reducing unnecessary energy consumption during transportation.

Pectinase Immobilization on a Chitosan-Coated Chitin Support

Abstract: Pectinase extracted from Aspergillus niger was immobilized on a chitosan-coated chitin support using various methods: immobilization by adsorption (P-QQSA), adsorption on supports activated by 0.5 and 15% glutaraldehyde (w/v) (P-QQSA 0.5 and P-QQSA 15) and covalent attachment to this support using 1% glutaraldehyde (P-QQSA 1). The optimum conditions selected for immobilization were pH 4.5, incubation time of 4 h and protein concentration of 340 μg/mL. Various characteristics of the immobilized pectinase such as optimum pH, heat stability and reusability were evaluated. As a result of immobilization the enzyme's T50 increased, the best being achieved with immobilization using 15% glutaraldehyde and covalent attachment. The optimum pH of the free and immobilized enzymes were 5 (free), 4.5 (P-QQSA), 4.5–5.0 (P-QQSA 0.5) and 4–5 (P-QSA 1 and P-QQSA 15), respectively. The biocatalysts prepared retained 100% of their original catalytic activity after nine cycles of reuse. Practical Applications Pectinases hydrolyze pectin and/or pectic acid. These enzymes have widespread applications in the food industry (processing of fruits), wastewater treatment, textile industries, fruit softening and plant infection processes. The stability of these enzymes depends on the aqueous medium and is easily disrupted to the point where the enzymes cannot function appropriately. Immobilization techniques provide a promising approach to retain their stability. Various methods for immobilization of this enzyme have been described: entrapping in alginate, physical adsorption on anion resin, γ-alumina, particles and nanoparticles of silica and covalent attachment to carriers such as porous glass and nylon. However, the development of new methods and supports for immobilizing enzymes is of special importance in enzyme technology. The present article describes several methods for immobilization of pectinase in chitosan-coated chitin for use in the juice and wine industries.

Effects of Drying Methods on the Aroma Components and Quality of Capsella Bursa‐Pastoris L

Abstract: Capsella bursa-pastoris L. (C. bursa-pastoris) was treated by hot air drying, microwave drying, vacuum drying and freeze-drying, respectively, to analyze the influences on aroma components using gas chromatography-mass spectrometry. The results showed that the freeze-dried product enjoyed significantly alleviated color changes, short rehydration time, high rehydration ratio and retention rates of chlorophyll and vitamin C. Vacuum drying functioned inferior to freeze-drying but superior to hot air drying and microwave drying. As for aroma components, both vacuum drying and freeze-drying managed to preserve the characteristic aroma components in C. bursa-pastoris. In summary, vacuum drying and freeze-drying retained the color, texture, morphology as well as grass and leaf aromas of C. bursa-pastoris in maximum, but the former method, which lasts a shorter time and consumes less energy, should be given first priority in large-scale industrial practice. Practical Applications C. bursa-pastoris suffers from a plummet of nutritional value and loss of economic benefits even within short harvest and storage periods. Drying newly harvested C. bursa-pastoris with appropriate techniques can both meet different consumer demands and effectively prolong the shelf life of products. Various drying techniques are bound to affect sensory attributes and retention rates of nutrients and aroma components significantly. We treated fresh C. bursa-pastoris by vacuum drying, hot air drying, microwave drying and freeze-drying, and compared the quality of final products, aiming to find out the optimum drying method and parameters and while providing valuable practical evidence for industrial drying of this vegetable.

Milling of Glutinous Rice by Semidry Method to Produce Sweet Dumplings

Abstract: To investigate the effects of semidry milling method on the quality attributes of glutinous rice flour and sweet dumpling, the glutinous rice flour were prepared by wet, dry and semidry milling, respectively. As a result, the content of damaged starch in dry-milled rice flour was significantly higher than that in wet-milled rice flour (P < 0.05). When the rice was tempered to 33% moisture, the content of damaged starch of semidry-milled glutinous rice flour was the same as that of wet milling. The wet-milled rice flour and semidry-milled glutinous rice flour at 33% moisture showed similar microstructures. The semidry milling at 33% moisture had properties of texture and cooking of sweet dumplings similar to wet milling. These results indicated that the semidry milling at 33% moisture showed protective effects on the characteristics of glutinous rice flour and qualities of sweet dumplings by reducing the degree of starch damage and protecting the integrity of the starch granules. Practical Applications The findings in the present study demonstrated the beneficial effects of semidry milling method on the qualities of glutinous rice flour and sweet dumplings. The semidry milling at 33% moisture showed better characteristics of glutinous rice flour and qualities of sweet dumplings by reducing the degree of starch damage and protecting the integrity of the starch granules. Therefore, the present study demonstrated a new milling method comparable to wet milling for standardization and large-scale industrial production of sweet dumplings.

The Drying Kinetics and Polyphenol Degradation of Cocoa Beans

Abstract: This study investigated the kinetics of drying and polyphenol degradation during hot air and sun drying of cocoa beans. Hot air drying was carried out using a constant humidity-controlled (50% relative humidity) oven at temperature range of 60–80C, and sun drying was carried out by exposing the beans under direct sunlight. Several semi-theoretical models were used to model the kinetics of moisture diffusion and it was found that the Page and Logarithmic models were able to provide good prediction. A first-order reaction kinetics was used to predict the polyphenol degradation process with rate constants ranging from 0.011/h to 0.052/h. Activation energy for polyphenol degradation was determined at 8.97 kJ/mol using the Arrhenius equation. Effective diffusivity during drying was found within the order of magnitude (10−12–10−10 m2/s) reported in most drying literatures. Practical Applications The understanding of moisture diffusion is important in dryer design especially in the determination of effective diffusivities during drying. Polyphenols are important antioxidants that are beneficial to human health. By investigating the polyphenol degradation kinetics, this helps to link the reactions with moisture diffusion kinetics.

Effects of Precooling with Slurry Ice on the Quality and Microstructure of Anglerfish (Lophius americanus) Liver

Abstract: The effects of precooling with slurry ice on the quality and microstructure of anglerfish liver were determined during further storage at −1.5C. The results showed that compared with the samples directly frozen at −1.5C (group B), precooling with slurry ice (group A) can significantly reduce the cooking loss (P < 0.05) from the third day, reduce the total volatile basic nitrogen and trimethylamine contents during early ice-temperature storage and slow down the change of PH. The odor significantly changed at days 5 and 7 of storage in samples from groups B and A, respectively. The hardness, elasticity, cohesiveness and chewiness of group B samples decreased sharply with storage time, but those of group A samples slightly decreased. Scanning electron microscopy showed that precooling with slurry ice delayed samples tissue damage. The experimental results indicate that refrigeration combined with precooling with slurry ice can satisfy the demand for long-distance transport of fresh anglerfish liver. Practical Applications Efficient preservation of anglerfish liver, which is nutritional and delicious, is more important for the economic viability of the aquatic foods industry. Slurry ice is the most effective technology to relevant increases in the shelf life of various chilled aquatic food products because of subzero storage temperature and fast chilling rates and less physical damage caused by microscopic spherical particles. In this study, the effects of precooling with slurry ice on the quality and microstructure of anglerfish liver were determined during further storage at −1.5C. The sensory, chemical and microstructural properties of anglerfish liver were determined by investigating the cooking loss, pH and contents of total volatile basic nitrogen and trimethylamine using electronic nose analyses, texture profile analysis, and scanning electron microscopy. This study aimed to improve the quality of fresh anglerfish liver by providing basic knowledge of precooling with slurry ice.

Effects of mechanical and enzymatic pretreatments on extraction of polyphenols from blackberry fruits

Abstract: Producing added value from under-utilised tropical fruit crops with high commercial potential//PAVUC/

Brewing Jujube Brandy with Daqu and Yeast by Solid-State Fermentation: Solid-State Fermentation of Jujube Brandy

Abstract: Chinese Junzao jujube in Xinjiang is a high-quality brew resource because of its high sugar content Jujube paste was hydrolyzed by a multi-enzyme and then fermented with Daqu and yeast through a solid-state fermentation process After distilling and aging, the final product has a typical characteristic of brandy The optimal hydrolysis conditions were a mixture of pectinase and cellulase with a ratio of 1:3, a dosage of multi-enzyme of 075% (w/w), an enzymolysis pH of 35–40, a temperature of 50C and a time of 3 h The optimal fermentation process was as follows: active dry wine yeast-SY yeast strain, dosage of yeast of 05%, dosage of Daqu of 18%, fermentation temperature of 25C and fermentation time of 21 days After distilling and aging, the alcohol content was 515% (v/v) and gas chromatography-mass spectrometry (GC-MS) analysis demonstrated that the final product has rich, unique flavor characteristics The results indicated that Daqu and solid-state fermentation can promote and enrich the flavor formation of jujube brandy Practical Applications Jujube output increases rapidly in China, especially in the Xinjiang area, but the development of process technology and high value-added products of jujube is lacking The present study provides a new process of brewing brandy with jujube The results indicated that the enzymatic hydrolysis of raw jujube before fermentation was beneficial for its utilization The solid-state fermentation process was feasible for brewing jujube brandy; by combining a mixed strain of yeast and Daqu, a rich flavor of brandy was produced This process should be a good example for brewing brandy products produced by other types of fruits

Establishment of an Enzymatic Membrane Reactor for Angiotensin-Converting Enzyme Inhibitory Peptides Preparation from Wheat Germ Protein Isolates

Abstract: In this paper, an efficient enzymatic membrane reactor (EMR) was established for the preparation of angiotensin-converting enzyme (ACE) inhibitory peptides from wheat germ protein isolates (WGPI). It promoted the protein conversion and improved the enzyme utilization rate. ACE inhibitory peptides of WGPI were prepared using 5 kDa membrane device for enzyme membrane coupling. Based on the results of the protease activity preservation experiment, substrate intercept experiment, batch EMR experiment and continuous EMR experiment, the conditions of EMR were decided as follows: substrate concentration of 1.2% (w/v), alcalase quantity of 110 μL, temperature of 50C, pH of 9.0, effective volume of 0.4 L, permeation flux of 0.005 L/min and turn into 0.011 L/min after 10 min and runtime of 300 min. The continuous EMR method showed high conversion rate of protein (55.3%) and IC50 of peptides (0.50 mg/mL). The conversion rate of protein significantly increased by 36.17% and the IC50 of peptides significantly reduced by 30.6% compared with the traditional enzymatic hydrolysis method. Therefore, the continuous EMR is beneficial to the efficient production of ACE inhibitory peptides from WGPI. Practical Applications Using food protein as raw material, functional polypeptides products have been developed by employing enzymatic hydrolysis and series of high technologies. However, during the preparation of functional polypeptides, some problems of low reaction efficiency, product yield and product activity existed, which seriously influence the performance of technology industrialization. The enzymatic membrane reactor (EMR) is an effective mode which can achieve continuous operation by the integration of substrate enzymolysis, enzyme recovery and hydrolyzate separation in functional polypeptides producing. Utilization of the EMR technology will not only increase food protein commercial value, but will also satisfy the needs of the polypeptide processing industries for efficient, low-cost producing.