Showing papers in "Journal of Food Processing and Preservation in 2017"

Effect of heat processing on thermal stability and antioxidant activity of six flavonoids

Abstract: The objective of this paper is on the one hand to study the effect of heat processing (30 to 130°C for 2 h) on the stability and antioxidant activity of six flavonoids (rutin, naringin, eriodictyol, mesquitol, luteolin, and luteolin 7-O glucoside), and on the other hand to establish the relation structure–activity–stability of these compounds. The dependency on temperature of the six kinetics was well described by the Arrhenius law and the main parameters provided by this model are determined and compared in this paper. Activation energies found were 107.3 kJ/mol for rutin, 100.6 for naringin, 33.3 for mesquitol, 68.2 for eriodictyol, 51.4 for luteolin, and 120 for luteolin 7-O-glucoside. The data collected showed that glycosylated flavonoids are more resistant than aglycon flavonoids to heat treatment. Moreover, it was also observed that despite the total degradation of some flavonoids, the treated solutions still have an antioxidant activity. Practical application Flavonoids are mainly consumed in processed foods. Thus, flavonoids often undergo heat processing. Knowing the thermal stability and the evolution of their antioxidant activity are particularly relevant in the field of food processing. The results of this study allow information to be collected on the relationship between heat stability-flavonoid structure and antioxidant activity. This information will be useful for the formulation of new food products or for the design of new food processes.

Encapsulation of clove essential oil in hydroxypropyl beta‐cyclodextrin for characterization, controlled release, and antioxidant activity

Abstract: The aim of this study was to investigate the physicochemical characteristics, release behavior, and antioxidant activity of clove essential oil-hydroxypropyl beta-cyclodextrin (CEO-HPβCD) inclusion complexes. Clove essential oil was encapsulated by the kneading method with hydroxypropyl beta-cyclodextrin in a 1:1 molecular ratio. The entrapment efficiency of the encapsulated particles was 97.04% ± 1.57. The average particle size was 165.87 ± 1.65 nm and polydispersity index was .25 ± .03. In vitro release profile of CEO-HPβCD inclusion complexes indicated slow and sustained release. DPPH scavenging activity of free clove essential oil and encapsulated particles was 25.20% ± 1.02 and 28.70% ± .77, respectively. Total phenolic content of free clove essential oil was 18.59 ± 1.60 mg GAE/100 mg oil while total phenolic content of particles was 22.57 ± 1.48 mg GAE/100 mg oil. The results of the study revealed that using hydroxypropyl beta-cyclodextrin to encapsulate clove essential oil can be beneficial for the food and pharmaceutical industries. Practical applications Clove essential oil has many biological activities due to its major compound eugenol. Choosing the appropriate method is a significant step for keeping active constituents. Encapsulation that is a beneficial process to control of the bioactive components can prevent degradation and loss of active compounds and prolong the shelf life of entrapped materials. This study can lead to use kneading method which is a low cost and easy encapsulation technique, for conservation of volatile active components, so these compounds can be used more intensely in the form of powder.

Pineapple Wines Obtained from Saccharification of its Waste with Three Strains of Saccharomyces cerevisiae

Abstract: This work aims to report on the processing of pineapple (Ananas comosus) peel and core into quality wines by combining physical and enzymatic treatments of waste and alcoholic fermentation of the pineapple must with three strains of Saccharomyces cerevisiae (TT, AW, EM2) at three different temperatures (25C, 20C, 15C). The main parameters of the alcoholic fermentation (yeast growth, ethanol production and sugar consumption) were monitored; the fixed and the volatile compounds of pineapple wines were characterized by means of HPLC and GC-MS techniques. Results outlined that the highest levels of ethanol, i.e., more than 7 and 8% vol/vol, were reached in 96 h when the fermentation was carried out at 20 and 25C with AW and TT strains, respectively. Differently, the fermentation at 15C with EM2 achieved the highest ethanol concentration (7.60% vol/vol) after 120 h and maintained higher levels of citric and malic acid. Accordingly, as the ethanol increases a simultaneous decrease in simple sugars was observed: glucose fell faster than fructose and reached concentrations below 1 g/L after 120 h of fermentation. Significantly different aroma profiles were measured in the wines by changing temperature and strain of S. cerevisiae: the fermentation with AW at 20C produced the highest concentration of acetate and ethyl esters that increased the fruity character of pineapple wine, whilst varietal aroma was enhanced by both fermentations at 25C and 15C with TT and EM2, respectively. However, no variations in pH and acidity during fermentation and very low levels of acetic acid in any pineapple wine sample stressed the aptitude to human consumption of pineapple wines obtained from pineapple waste under this study. Practical Applications Outcomes of the study are important to the industry and highlighted the feasibility of processing tropical fruit waste to obtain added value food products. Furthermore, the results of this work updated the small amount of information published to date on the processing of pineapple waste (or of other tropical fruits) into food grade products, and on the volatile compounds of pineapple wine. As a consequence, the process of conversion of pineapple waste into wine when properly scaled-up may be transferred to industries that are located either in tropical areas, or in developing countries where the waste is not utilized yet.

Active biodegradable film with encapsulated anthocyanins: Effect on the quality attributes of extra-virgin olive oil during storage

Abstract: The aim of this study was to verify the effectiveness of an active biodegradable film on the maintenance of extra-virgin olive oil (EVOO) quality attributes. Level of peroxides, acidity, K232, color, chlorophylls, and carotenoids were determined as parameters to verify the oil quality over storage period. Maltodextrin was used to encapsulate anthocyanins and was the major component in the films, which were used as pouches to pack the oil. The samples were stored at 40°C, exposed to fluorescent light, and monitored during 12 days. The film successfully maintained the quality of EVOO under the limits established by Codex Alimentarius for over 8 days (13.6 meq O2/kg of peroxides at the 8th day), while the oil packed in polypropylene pouches was degraded before the 4th day of storage (326.5 meq O2/kg). Therefore, the results demonstrated the effectiveness of the film on maintaining the quality of EVOO and its promising application as active packaging. Practical application Extra-virgin olive oil (EVOO) is an oxidation-sensitive product and has been shown to quickly deteriorate when stored under less than ideal conditions. The study brings a new packaging possibility to the commercialization of EVOO with longer shelf-life. The storage of extra-virgin olive oil in biodegradable pouches produced with anthocyanins could preserve EVOO from oxidation and consequently extent its shelf-life. The study proves the efficacy of an active biodegradable packaging on maintaining quality attributes of EVOO. The commercialization of EVOO in active biodegradable pouches could be an eco-friendly and sustainable way to bring health and practicality to consumers.

Integration of design of experiment, surface response methodology, and multilayer validation to predict the effect of blanching on color of tomato juice

Abstract: Response surface methodology was used to develop models to predict the effect of tomato cultivar, juice pH, blanching temperature, and time on color change of tomato juice after blanching. The juice from three tomato cultivars with adjusted pH levels ranging from 3.9 to 4.6 were blanched at temperatures from 60 to 100 °C for 1–5 min using the central composite design (CCD). The color change was assessed by calculating the redness (a/b) and total color change (ΔE) after measuring the Hunter L, a, and b values. Developed models for both redness and ΔE were significant (p < .0001) with satisfactory coefficient of determination (R² = .99 and .97) and low coefficient of variation (CV% = 1.89 and 7.23), respectively. Multilevel validation that was implemented revealed that the variation between the predicted and experimental values obtained for redness and ΔE were within the acceptable error range of 7.3 and 22.4%, respectively. PRACTICAL APPLICATIONS: Thermal blanching is an essential pretreatment carried out extensively in tomato juice processing industry. Scientific evidence and experience show that fruit variety or cultivar and the exact blanching conditions can affect either positively or negatively the tomato juice color, the most important quality attribute of the product. Therefore, optimization of blanching conditions as performed using the current thermal technology in order to obtain desired color properties is still very important. In this study the impact of tomato cultivar, juice pH, and blanching conditions (temperature and time) on the color of tomato juice after blanching was evaluated and models have been developed that predict the redness and color change after processing. The models were incorporated into an access web tool we developed that could be beneficial in optimizing the processing conditions for a particular tomato cultivar in an industrial environment.

Effect of Palletized Map Storage on the Quality and Nutritional Compounds of the Japanese Plum cv. Angeleno (Prunus salicina Lindl.)

Abstract: The influence of active modified atmosphere packaging MAP (10.0 kPa of O2 and 5 kPa of CO2) on palletized system was evaluated to extend the marketability of fresh plums cv. Angeleno. Fruits were wrapped with a polyethylene film in pallet bag units at 1C and 90% relative humidity for up to 60 days. The gas values of the pallet bags, the fruit weight losses and their qualitative and nutraceutical characteristics were periodically monitored to evaluate the goodness of storage. The results showed as the pallet bag have maintained the market life of Angeleno plums to up to 60 days, preserving the most important qualitative traits of fruits. After 20, 40 and 60 days the MAP treatment maintained the pulp harder than control fruits respectively of 0.87, 0.75 and 0.46 kg/cm2 and the SUAC index (quotient of the sum of sugars and sum of acids) was unaffected by the gas composition. Pratical Applications The storage in pallet under different MAP conditions could be a promising technique for plums and specifically allows different items with different technical requirements to be stored in the same cold-storage room. Furthermore, the storage units could also be conveniently used for the fruit transport along the entire supply chain to reach markets far from production areas.

Influence of antibrowning solutions, air exposure, and ultrasound on color changes in fresh-cut apples during storage

Abstract: This study identified optimal apple cultivars and antibrowning treatments with/without ultrasound for fresh-cut processing with minimal color changes observed during storage. Color changes ( ΔEa,b∗) were evaluated for various apple cultivars (Idared, Golden Delicious, Gala, Gloster, Cripps Pink, Braeburn, and Fuji) treated with different antibrowning solutions (ascorbic + citric acid; ascorbic acid + NaCl; NaCl, citric acid, and Ca-ascorbate) with/without ultrasound during storage of 24 hr. Also, sensory evaluation was conducted to assess the acceptability of treated apples. The effectiveness of antibrowning treatments with or without ultrasound were determined as negative effect on ΔEa,b∗ and browning index over the storage. The best apples were Cripps Pink and Golden Delicious, and solutions were Ca-ascorbate and ascorbic + citric acid. In combination with ultrasound, the best solution was Ca-ascorbate. Exposure to ultrasound confirmed the best suitability of Ca-ascorbate and Cripps Pink for fresh-cut, while implying that longer periods of exposure might be beneficial for prevention of browning in fresh-cut apples. Practical applications Fresh-cut processing is a significant segment of the worldwide food markets, with fresh-cut apples being one of the most important foods for such production. Fresh-cut apples have short shelf-life that is mainly reduced by browning. Since, profit margin in fresh-cut industry is spread over the short periods of time (largely due to short shelf-life) it is crucial for such industrial processing to identify apples and antibrowning treatments that will extend preservation to longest possible time while assuring consumer acceptance of such products. Simultaneously, it is important to detect advanced nonthermal treatments able to reduce or prevent browning in fresh produce with minimal loss in nutritive value and addition of additives, due to consumers’ tendency to demand such foods.

Comparative Study of the Effects of Processing on the Nutritional, Physicochemical and Functional Properties of Lentil

Abstract: The effects of processing (dry-milling, cooking, isoelectric precipitation) on the physicochemical, functional and nutritional properties of lentil were evaluated. Protein, moisture, lipid and ash contents of raw lentil flour (RLF), cooked lentil flour (CLF) and lentil protein isolate (LPI) ranged between 29.2 and 90.6%; 0.5 and 6.7%; 0.1 and 0.7%; and 2.4 and 3.4%, respectively. LPI contained smaller particles with narrower size distribution than CLF or RLF. RLF contained less lysine but had more determined sulfur-containing amino acids than the CLF. LPI and CLF, respectively, showed the highest and lowest solubility between pH 1 and 12. Water holding and fat absorption capacities were highest for LPI followed by CLF and RLF. Circular dichroism and FTIR spectroscopy showed minimal secondary structural changes in RLF and LPI compared with CLF. Anti-nutritional factors content and thermal properties revealed distinct variations between the two flours and protein isolate. Processing of lentils could be explored to modify its functionality for various food applications. Practical Applications This article presents simple processing methods (dry-milling, cooking and isoelectric precipitation) to modify and obtain value-added lentil products with improved physicochemical, functional and nutritional characteristics. Such processing approaches could markedly influence the value of lentil, diversify it use, and help to improve the competitiveness of the pulse sector. Research Highlights Milling, cooking and protein extraction modified the properties of lentil The protein-rich lentil isolate had low phytic acid and trypsin inhibitor content Protein solubility, water holding and fat absorption were improved in the isolate Amino acid content and quality of protein were highest in the protein isolate

Comparison of Ultrasound and Maceration Techniques for the Extraction of Polyphenols from the Mango Peel

Abstract: An investigation was carried out to extract the polyphenols from mango peels by ultrasound-assisted extraction (UAE) and maceration techniques and to assess the antioxidant potential and quantification of phenolic compounds by high performance chromatography. Results showed that highest extraction yield obtained through solvent methanol at 80% concentration level while ultrasound-assisted extraction was more efficient technique and led to comparatively higher polyphenols content than maceration. Highest polyphenols were extracted with 80% ethanol (67.58 mg GAE/g of extract) by employing UAE whereas least polyphenols (18.66 mg GAE/g of extract) were obtained with 100% ethyl acetate through maceration technique. The high antioxidant activity of mango peel extracts was exhibited in three antioxidant assays with 80% ethanolic extracts had the highest antioxidant activity 31.51 + 0.79 mM/100 g for ferric reducing antioxidant power, highest scavenging activity 83.19 + 0.96% and 67.23 + 0.85% for 2,2-Diphenyl-1-picrylhydrazyl and superoxide anion radical assays, respectively. Strong correlations between total polyphenols and antioxidant activity were observed. Practical Applications Polyphenols are the natural antioxidants in plants having a significant role in human health by prevention of certain oxidative stress-related diseases. Mango peels are the major agro-industrial wastes in fruit juice processing which are not further utilized despite being an abundant source of phenolic compounds even more than the mango pulp. The study revealed that mango peels as a potential source of phenolic compounds which may be utilized as an ingredient for the preparation of functional foods.

Optimization of ultrasound‐assisted extraction conditions for recovery of phenolic compounds and antioxidant capacity from banana (Musa cavendish) peel

Abstract: A large quantity of banana peel is generated annually and is considered as waste with low value. This study aimed to optimize five extraction parameters; including ultrasonic temperature, time and power, as well as acetone concentration and sample to solvent ratio, for maximum recovery of phenolic compounds, flavonoids, proanthocyanidins and antioxidant properties from banana (Musa cavendish) peel using response surface methodology. The results showed that recovery yields of phenolic compounds, flavonoids, proanthocyanidins and antioxidant properties were affected by the extraction parameters; of which the acetone concentration had the greatest effect. Optimal extraction conditions were found to be at ultrasonic temperature of 30°C, ultrasonic time of 5 min, ultrasonic power of 150 W, sample to solvent ratio of 8:100 g/mL and acetone concentration of 60%. Under these optimal conditions, 23.49 mg of phenolic compounds, 39.46 mg of flavonoids and 13.11 mg of proanthocyanidins could be extracted from 1 g of banana (M. cavendish) peel. Practical applications Banana peel known as waste is generated in a big quantity with limited utilization. Therefore, it is necessary to utilize this by-product for adding value to food industry. This study was designed to establish a simple, effective extraction method for maximum recovery of phenolic compounds from banana peel. Findings from this study can be used for further isolation and purification of phenolic compounds from banana peel for subsequent application in nutraceutical and pharmaceutical industry.

Contribution of Mixed Starter Cultures to Flavor Profile of Suanyu – A Traditional Chinese Low‐Salt Fermented Whole Fish

Abstract: The effect of mixed starter cultures isolated from Suanyu on flavor compounds development has been researched. Microorganism, pH, TA, sugars, nonvolatile organic acids and volatile compounds were analyzed in Suanyu with or without starters. In inoculated samples, a higher growth of lactic acid bacteria (LAB) and a declining rate of pH were determined when compared with the controlled samples. Besides, higher levels of volatile compounds were detected in inoculated Suanyu (19342.47, 19852.74 × 106 area units for PS) than those in controlled samples. During the process, aldehydes, acids, alcohols, esters and ketones were formed and increased continuously. Especially in Suanyu with PS, higher levels of ethanol (6973.8, 6549.9 × 106 area units) and acetic acid (2116.8, 2471.1 × 106 area units) were detected, which could produce unique wine flavor and moderate acid taste. Furthermore, high content of hexanal was generated through the addition of PS, which could contribute to a green grass odor. Practical Applications In this study, microorganism, pH, TA, sugars, nonvolatile organic acids and volatile compounds were analyzed in Suanyu with autochthonous starter cultures. The results showed that the generative stability of Suanyu can be assured and the product quality can be advanced by adding autochthonous starter cultures compared with that of noninoculated samples. There is a need to add modern processing technology such as microbial fermentation of the fermentation process to achieve effective control to ensure product flavor and product quality stability. In this study, autochthonous starter cultures isolated from Suanyu, which were propitious to the demand of industrialization. Besides, once the research is applied in the industrialized production, and considerable social and economic benefits can be obtained. Therefore, this study has a good prospect in application.

Mathematical Modelling of Osmotic Dehydration Kinetics of Apple Cubes

Abstract: Apple cubes were osmotically dehydrated at 25, 40 and 60C, using sucrose or sorbitol, and the mass ratio of sample to solution of 1:4 and 1:10, at atmospheric pressure or vacuum pressure of 150 mbar. Six mathematical models were tested to describe the mass transfer kinetics of water loss (WL) and sugar gain (SG). Crank's, Azuara's, Peleg's, Page's and Weibull's models could fit well the experimental data, but the Penetration model resulted in a poor fit. The mass ratio of sample to solution did not have an influence on the mass transfer kinetics at the atmospheric pressure. The increase of temperature and the use of sorbitol as the osmotic agent resulted in an increase of the osmotic process rate at both pressures used. Therefore, sorbitol is a good alternative to sucrose. The vacuum presented a tendency to increase the initial rate of WL. Practical Applications This work confirms the potential to use sorbitol as an alternative to sucrose as the osmotic agent in OD. Besides presenting low calories, and being less sweet and less cariogenic than sucrose, sorbitol is a prebiotic. It induced an increased process rate, in comparison with sucrose. This is advantageous for a faster OD process. However, the benefit in the process time reduction may not justify the material costs. The mass ratio of sample to solution of 1:4 was identified as an alternative to 1:10 in the OD at the atmospheric pressure, as lower quantities of osmotic solution and, therefore, solute are required to carry out the OD process to the same level of dehydration. This work shows also that simple models, such as Peleg's and Page's, can be used to predict the mass transfer kinetics of WL and SG during OD processes at different conditions.

Electrotechnologies, microwaves, and ultrasounds combined with binary mixtures of ethanol and water to extract steviol glycosides and antioxidant compounds from Stevia rebaudiana leaves

Abstract: The aim of this work was to investigate the potential use of non-conventional technologies (microwaves, ultrasounds, pulsed electric fields, and high voltage electrical discharges) to enhance the extraction of high-added value compounds (mainly stevioside and rebaudioside A), and antioxidants (total phenolic compounds, flavonoids, chlorophylls, and carotenoids), from Stevia rebaudiana leaves. After treatment at equivalent energy, a supplementary diffusion was performed until 1 h. Results demonstrated that when water (100%) was used as solvent, the maximum recovery of stevioside (50.8 ± 0.1 mg/g) was obtained after ultrasound-assisted extraction, while microwave allowed the highest yields of rebaudioside A (22.7 ± 0.1 mg/g). However, pulsed electric field technology was the most efficient to recover stevioside (44.2 ± 0.1 mg/g) and rebaudioside A (22.4 ± 0.3 mg/g) when using 50% ethanol-water. Results obtained through this work pave the way toward the possible scaling-up of some of these non-conventional technologies for a multistep selective extraction of valuable compounds from Stevia leaves. Practical applications Recovering high added value compounds (i.e. stevioside and rebaudioside A) from stevia leaves in food industry is usually performed using thermal extraction under agitation after drying and grinding. Although efficient, this technique generates an extract not only rich in targeted compounds but also in impurities, which complicates the downstream processing steps. Selective extraction of stevioside and rebaudioside A using non-conventional extraction technologies (i.e. pulsed electric field, etc.) may allow reducing the processing steps (grinding, downstream purification, etc.), and thus an alternative to the conventional method. For this reason, investigating the impact of these technologies at laboratory scale to recover target molecules from stevia leaves is of paramount importance before scaling up the process.

Prediction models for the softening of new commercial Actinidia cultivars

Abstract: Empirical models for the softening of Actinidia deliciosa fruits (exponential decay, complementary Gompertz and modified Boltzmann models) were applied to the ‘Hortgem Tahi®’ and ‘Hortgem Rua®’ cultivars of Actinidia arguta (Seib. Et Zucc.) Planch. Ex Miq, and the ‘Jingold®Jintao’ cultivar of Actinidia chinensis Planch., all of which are emerging cultivars in the baby kiwi and yellow pulp kiwifruit markets. A texture analyser collected firmness data for kiwifruits stored up to 18 days at 2 and 24°C, for use in prediction models. The dry matter, soluble solid, and vitamin C content was also determined for these new commercial cultivars, which were compared to the control ‘Hayward’ cultivar. The Boltzmann model, which is known to perform well for the ‘Hayward’ cultivar, was confirmed as the best fit for baby kiwi ‘Rua®’ and yellow ‘Jingold® Jintao’ cultivars for all studied conditions, whereas the exponential decay model was the best fit for the ‘Tahi®’ cultivar. Practical applications In the postharvest sector, models or equations can represent effective tools for the prediction and characterization of physiological and qualitative changes during fruit ripening in different storage conditions. We evaluated the softening of new commercial cultivars of the Actinidia genus, which could improve our understanding of the behavior of these fruits under different temperatures, as well as allowing prediction of their shelf-life. Moreover, the evaluation of mathematical models on softening could facilitate the scheduling of the post-harvest management of kiwifruit. This would assist with managing this product for distant or demanding markets, as well as other operations such as packaging, where this information could help to reduce economic losses associated with excessive softening.

Improving the Textural Properties of Yogurt Fortified with Milk Proteins

Abstract: In this study, the changes in the physicochemical, textural and sensory properties of nonfat yogurts fortified with milk proteins; namely sodium caseinate (Na-CN), calcium caseinate (Ca-CN) and milk protein concentrates (MPCs) were investigated. Enrichment of nonfat yogurt with the milk protein additives had a noticeable effect on pH, titratable acidity, whey separation, water holding capacity (WHC), protein contents and color values as well as textural attributes such as hardness, adhesiveness and cohesiveness (P < 0.01). It can be seen that the addition of milk proteins have increased the WHC and decreased whey separation. Using milk proteins in yogurt manufacturing processes caused a more compact structure consisting of stiff casein particles and large aggregates along with increased hardness which also increase cohesiveness and elasticity values resulting in improved textural properties. Also chromatic parameters (L*, a*, b*, ΔE, h*, and C*), were affected by protein supplementation. The taste of samples enriched with milk proteins were more appreciated than control yogurt. These findings confirm that milk protein additives can play a beneficial role in improving textural properties of set type nonfat yogurt and can be used to develop functional dairy products. Practical Applications Yogurt is a popular fermented milk product of the human diet, due to their high nutritional value and their appealing sensory and textural properties. Textural properties of yogurt are known to have an important parameter on sensory and acceptability of yogurt. However, reduction of fat and total solids content in low fat and nonfat yogurts, exhibit weak texture, poor sensory properties. The aim of this study was to search the effects of using milk proteins on physicochemical, textural and sensory properties of nonfat yogurts. The results indicated that milk proteins caused an increase in density of the protein matrix with the structural building properties and improved textural properties.

Physicochemical and Thermal Stability of Microcapsules of Cinnamon Essential Oil by Spray Drying

Abstract: Many studies on the cinnamon essential oil has attracted the attention of researchers because of their antimicrobial and antifungal properties. The objective of this study was to evaluate the influence of different wall material on the physicochemical characteristics of microencapsulated cinnamon essential oil. Microcapsules produced with combinations of wall materials (gum arabic, whey protein isolate and maltodextrin) were evaluated with regard to moisture, solubility, hygroscopicity, bulk density, tapped bulk density and microscopic analysis. The encapsulation efficiency was based on cinnamaldehyde retention in relation to the content of the pure oil. The results showed that blends of gum arabic and maltodextrin obtained better retention of cinnamaldehyde (50%). The presence of maltodextrin together with whey protein isolate favored the formation of more spherical particles. Transmission electron microscopy images clearly showed the oil dispersed in the wall materials. Thermogravimetric curves showed higher thermal stability for microcapsules with whey protein isolated. Based on the physicochemical characteristics analyzed, the best wall material for the process of microencapsulation essential oils of cinnamon was the combination of gum arabic and maltodextrin. Practical Applications This paper aims to add knowledge about the microencapsulation process of essential oils, promoting greater stability to oils.

Investigating the Effects of Large-Scale Processing on Phytochemicals and Antioxidant Activity of Pomegranate Juice

Abstract: The effects of four important stages of pomegranate juice processing, ie, pasteurization, enzymatic treatment, filtration and thermal concentration were evaluated based on physicochemical characteristics, bioactive compounds (phenols, flavonoids and anthocyanins) and antioxidant activity (DPPH, FRAP and CUPRAC) Pasteurization had no significant effect on total phenolic content, but it significantly reduced the total flavonoid and total anthocyanin contents Enzymatic treatment, filtration and thermal concentration significantly reduced the total phenolic and total flavonoid contents Pasteurization and thermal concentration had no significant effect on FRAP and CUPRAC values The IC50 value increased notably during enzymatic treatment, filtration and thermal concentration Processing the pomegranate juice and the subsequent production of pomegranate concentrate led to an overall reduction of total phenolic content, total flavonoid and total anthocyanin contents by 68, 46 and 61%, respectively Moreover, the processing caused reductions in total antioxidant capacity by 27 and 9%, determined via the CUPRAC and FRAP methods, respectively Practical Applications Fruit juice processing (ie, pasteurization, clarification, filtration and concentration) exposes the phytochemicals present to different detrimental factors that may lead to undesirable alterations in bioactive compounds and antioxidant activity The possibility of change in bioactive compounds (phenols, flavonoids and anthocyanins) and antioxidant activity (DPPH, FRAP and CUPRAC) of pomegranate juice (PJ) during different stages of large-scale processing is an issue that is dealt with in this study

Antioxidant Activity and Stability Study of Peptides from Enzymatically Hydrolyzed Male Silkmoth

Abstract: The antioxidant activity and stability of peptides from male silkmoth hydrolysates (MSH) was studied as antioxidant ingredients in potential food applications. MSH were isolated into five fractions: MSH-I (MW > 30 kDa), MSH-II (10–30 kDa), MSH-III (5–10 kDa), MSH-IV (3–5 kDa), and MSH-V (<3 kDa) by ultrafiltration. The antioxidant activity, molecular weight distribution and amino acid contents of each fraction were evaluated. The effects of NaCl, temperature, pH, light intensity and simulated gastrointestinal digestion were assessed to determine the stability of peptides. The antioxidant capacity of MSH-I as a major antioxidant component was 1,950 µmol/g in ORAC assay and 275 µmol/g in DPPH scavenging method. MSH showed good stability when salinity was less than 4%, temperature below 60C, and pH between 4 and 8. The antioxidant activity could retain about 80% after simulated gastrointestinal digestion. In conclusion, the MSH is a promising resource for stable antioxidant peptides applied in functional food processing and storage. Practical Applications In sericulture, the total cocoon yield has been 738,100 tons, the silk yield has been 93,000 tons, even about 60,000 tons of tussah moth cocoons produced in China in 2005. However, accompanied by the ascension of the silk consumpution, the sonsiderable amount of by-product and sericulture waste presented rising trend yearly. While, moth as insect having allergy protein, which use has been limited, but it has an excellent protein and active peptides and other ingredients (to improve immunity and sexual function), comprehensive utilization of silkmoth turns into meaningful topics. Using enzyme technology or fermentation technology (Protein degradation) to develop its protein resource utilization in silkmoth becomes the effective tools to solve this problem. The present experiments studied antioxidant activity by ultrafiltration technology and stability study of peptides from enzymatically hydrolyzed male silkmoth.

Efficacy of Ozone Treatment on Mycotoxins and Fungal Reduction in Artificially Contaminated Soft Wheat Grains

Abstract: The effects of O3 concentration, exposure time and grain mass were evaluated on the levels of deoxynivalenol, aflatoxins and total fungal count (TFC) in wheat grains, using a full 23 factorial design. Grain samples were contaminated with fungal conidia and spiked with mycotoxins standards and then submitted to ozonation treatments. The most significant reductions obtained for deoxynivalenol and total aflatoxins corresponded to 64.3 and 48.0%, respectively. TFC reduced approximately 3.0 cycles log cfu/g of wheat grain. O3 concentration and exposure time influenced (P < 0.05) positively the reductions of both mycotoxins and TFC, while the grain mass had a negative effect on both responses. The most significant reduction in TFC and mycotoxin levels was achieved by using 60 mg/L of O3 for 300 min, with 2 kg samples. Gaseous O3 can be considered an excellent method for remediation of these contaminants. Practical Applications Gaseous ozonation is an interesting nonthermal technology that can be applied to reduce fungal and mycotoxin contamination in wheat grains (Triticum aestivum L.). The O3 concentration and exposure time positively influence reductions in mycotoxins and fungi count, while grain mass has a negative effect on both variables. Using 60 mg/L of O3 at 300 min of exposure and 2 kg grain samples (11.3% moisture content) is possible to obtain reductions of 3.0 cycles log cfu/g in total fungal count, 64.3% in DON levels and 48.0% in total aflatoxin levels. Data found in this research should contribute in greater interest of ozonation by the food industry and consequently a wider popularization of ozonized products by consumers.

Ohmic heating assisted polyphenol oxidase inactivation of watermelon juice: Effects of the treatment on pH, lycopene, total phenolic content, and color of the juice

Abstract: Fresh watermelon juice was treated at 90 8C by hot-water (HW) and ohmic (OH) treatment (with SS:316 electrodes) for 15, 30, 45 and 60 sec. PPO activity was reduced to 36.15 and 8.87% in 60 sec by HW and OH treatment respectively. The PPO inactivation was fitted to the first order model; the reaction constant (k), D90 obtained was 0.02 s21, 115.1 sec, and 0.062 s21, 37.1 sec for HW and OH treatment respectively. During both the treatments of watermelon juice total phenols (TPC) showed significant change whereas no significant change was observed in lycopene content. Total change in color (DE) during OH treatment was found lesser as compared to HW treatment, hue angle was found to increase at a higher rate in HW than that of OH treatment. Finally it was concluded that PPO of water melon juice can be inactivated rapidly by OH than HW treatment. Practical applications Enzymatic browning and lycopene degradation are the major factors that limit the storage of watermelon juice. High temperatures and processing times employed during thermal processing cause deleterious changes in the color, flavor, and sensory aspects of the product. Therefore, this study was conducted to investigate the comparative effect of ohmic and conventional heating on inactivation of PPO as well as quality changes in watermelon juice so as to suggest a time-efficient alternative that can be explored further for commercial packaging.

Utilization of Apple Pomace in the Preparation of Fiber‐Enriched Acidophilus Yoghurt

Abstract: Dried apple pomace contains 36.8% fiber composed of water soluble and insoluble fractions, but is treated as a waste in apple processing industries. The present study was conducted to prepare fiber-enriched yoghurt by using 2.5, 5, 7.5 and 10% apple pomace fiber in whole milk and milk without fiber was kept as the control. All the treatments were inoculated with combined culture (1%) of Lactobacillus acidophilus and Bifidobacterium longum. The yoghurts were evaluated in terms of sensory quality, pH, acidity, total solids and fiber contents. The addition of fiber in yoghurt resulted in a decrease of acidity (0.15–0.09%) and fat contents (1.65–1.59%) with increase in fiber concentration. Further, on the basis of sensory analysis, yoghurt containing 5% apple fiber was judged as the best and hence optimized for preparation of fiber-enriched acidophilus yoghurt with desirable quality and sensory attributes. Practical Applications The diets with high content of fiber have been reported to have a positive effect on health. The importance of food fibers has led to the development of a large and potential market for fiber-rich products and ingredients. Recently, there is a trend to find new sources of dietary fiber that can be used in the food industry. Supplementation has been used to enhance fiber content of foods. Addition of fiber in breakfast cereals, bread, cookies, cakes, yogurt, beverages and meat products has been reported with favorable qualities. The present manuscript was carried out keeping in view the positive effect of fiber on human health.

Lactobacillus plantarum WCFS1 Fermentation Differentially Affects Antioxidant Capacity and Polyphenol Content in Mung bean (Vigna radiata) and Soya Bean (Glycine max) Milks

Abstract: The antioxidant capacity and polyphenol content in mung bean (Vigna radiata) and soya bean (Glycine max) milk fermented by Lactobacillus plantarum WCFS1 were investigated. Fermentation had different effects on antioxidant capacity in the lipophilic and hydrophilic fractions of two bean milks. Further, the free radical scavenging capacity was much higher in the lipophilic fraction than in the commonly investigated hydrophilic fraction of both fermented bean milks. Total phenolic content in both fermented bean milks increased. HPLC and LC-MS/MS analyses found that vitexin and isovitexin were the main phenolic compounds in the fermented and nonfermented mung bean milk, and fermentation did not significantly change their contents. Practical Applications Fermentation of bean milk by lactic acid bacteria (LAB) has been of increasing attraction to food scientists. Herein, we highlighted that LAB Lactobacillus plantarum WCFS1 was efficient for the fermentation of mung bean and soya bean milks, and the two fermented bean milks contained substantial antioxidant polyphenols, especially the fermented mung bean milk, which was rich in vitexin and isovitexin, two flavones with a number of bioactivities. Therefore, L. plantarum WCFS1 can be a good candidate for the fermentation of edible bean milks and fermented bean milks containing antioxidant polyphenols can be developed into functional drinks with enhanced health benefits.

Comparison of Drying Characteristics and Quality of Peppermint Leaves Using Different Drying Methods

Abstract: In this study, we investigated the effects of hot air, infrared and combined hot air-infrared drying methods on the drying time, energy consumption, color, rehydration and oil content of peppermint leaves. Three different air temperatures (30, 40 and 50C) and air velocities (0.5, 1 and 1.5 m/s) were used in the hot air drying. Infrared drying process was implemented using three levels of radiation intensity (1500, 3000 and 4500 W/m2), three distances between emitter and sample (10, 15 and 20 cm) and three air velocities (0.5, 1 and 1.5 m/s). The results showed that the optimum drying period and energy consumption were obtained when infrared- and hot air-drying were applied simultaneously. The results also showed that combined drying resulted in dried leaves of superior quality when compared to the leaves dried separately by either hot air alone or infrared, exhibiting lower total color change, greater rehydration ratio and higher extraction oil yield. Practical Applications Peppermint leaves are highly valuable products with wide range of industrial uses but extremely perishable in normal surrounding temperature-humidity conditions too. This fact makes their preservation important. Drying is a common preservation method that is applied to foods and agricultural products. Hot air has been traditionally used for drying peppermint leaves; however, infrared radiation has been employed for this purpose recently. However, there is very little knowledge, if none, on the use of combination of hot air and infrared drying method on the drying performance as well as the quality of final dried leaves. We treated fresh peppermint leaves by hot air drying, infrared drying and combined hot air-infrared drying, and compared the quality of final products and energy consumption during drying, aiming to find out the optimum drying method and drying parameters; while are beneficial to related industry in drying this valuable product. Our research work confirmed that combined hot air-infrared drying is a good alternative instead of the use of hot air drying or infrared drying separately.

Hot air drying and freeze drying pre‐treatments coupled to explosion puffing drying in terms of quality attributes of mango, pitaya, and papaya fruit chips

Abstract: To further improve the quality of traditional combined hot air and explosion puffing drying (AD-EPD) dehydrated tropical fruit, freeze drying, as a pre-drying treatment, combined with explosion puffing drying (FD-EPD) was applied to dry mango, pitaya, and papaya fruit. Comparative study of AD-EPD and FD-EPD in terms of physicochemical, texture, color, microstructure, and rehydration properties of the three tropical fruit chips was done. Compared with AD-EPD, the crispness and the volume ration of the three tropical fruits were significantly improved when EPD coupled with FD. The lowest color difference, as well as high retention of physicochemical characteristics was found in FD-EPD prepared chips. The improvements of texture and color in FD-EPD dried fruit chips were confirmed using a 15-member sensory evaluation. In terms of integrated quality of the three tropical fruit chips, FD-EPD could be further applied to process valuable materials. Practical applications Drying has been applied to extend the shelf-life of seasonable fruit. With the development of drying industry, more and more advanced drying technologies are required. Explosion puffing drying (EPD) is a novel drying technology, which has many advantages, such as improving product's quality, increasing the drying rate and reducing the cost. Freeze drying (FD), as one of the innovative drying methods can be applied to combine with EPD (FD-EPD) to dry tropical fruit (mango, pitaya, and papaya). The tropical fruit chips dried by FD-EPD are presented integrated quality. Overall, FD-EPD will be a promising drying technology for preparing tropical fruit chips.

Drying of Garlic Slices (Allium Sativum L.) and its Effect on Thiosulfinates, Total Phenolic Compounds and Antioxidant Activity During Infrared Drying

Abstract: This study was conducted to evaluate moisture transfer and changes of thiosulfinates, total phenolic compounds and antioxidant activity of garlic slices during infrared drying at temperatures from 50 to 80C and powers from 675 to 2,025 W. Drying time was significantly shortened with increasing infrared drying temperature. Thiosulfinates showed no significant changes versus moisture content during the whole drying period at 50, 60 and 70C, while a notable degradation of thiosulfinates was observed at 80C. Total phenolic compounds in garlic slices all rapidly decreased versus moisture content initially at all investigated drying conditions. Whereas the total phenolic compounds in dried garlic slices significantly enhanced with drying temperature from 50 to 80C at 1,575 W. Antioxidant activity increased during infrared drying, which was contradictory with the changes of total phenolic compounds and thiosulfinates. Pratical Applications This work are useful for the processing of garlic slices by infrared drying to obtain the optimum benefits of bioactive compounds present in this food product during drying. Infrared drying is reported as a promising method on foodstuff processing, which impinges on the material, penetrates it, and converts the infrared energy into heat. Therefore, it is more energy saving as well as reduce drying time. In this study, drying time was significantly shortened with increasing infrared drying temperature. A remarkable decrease of total phenolic compounds versus moisture content was observed during infrared drying. Meanwhile, thiosulfinates of garlic showed fluctuation over the moisture content decreased, except a notable degradation of thiosulfinates was observed at 80C. Conflicting results were found in antioxidant activity that a clear increasing trend with decreasing moisture content during infrared drying process.

Utilization of Tuna Processing Byproducts: Protein Hydrolysate from Skipjack Tuna (Katsuwonus pelamis) Viscera

Abstract: Alcalase showed optimum activity against skipjack tuna (Katsuwonus pelamis) viscera at pH 10 and 65C. Enzyme concentration, reaction time and fish viscera/buffer ratio affected the degree of hydrolysis (DH) (P < 0.05). Hydrolysis with an enzyme level of 3% (w/w) for 20 min with fish viscera/buffer ratio of 1:2 (w/v) was found to be the optimum condition. Protein, lipid and ash content of freeze-dried hydrolysate were 81.04, 6.78 and 12.01% dry weight basis, respectively. It was brownish yellow in color (L* = 62.46, a* = 1.44 and b* = 23.05). The hydrolysate contained a high amount of essential amino acids (43.13%) and had glutamic acid, methionine and aspartic acid as the dominant amino acids. Therefore, protein hydrolysate derived from skipjack tuna viscera could potentially serve as a good source of peptides and amino acids and the production of tuna waste protein hydrolysate has both ecological and economical advantage for the tuna industry. Practical Applications Efficient utilization of fish byproducts, especially viscera, is important for the economic viability of the aquatic food industry. Enzymatic hydrolysis is one of the most effective technologies for recovering value-added proteins from fish viscera without losing their nutritional value. In this study, protein hydrolysate prepared from skipjack tuna viscera using Alcalase showed high protein content. Hence, it can be used in a wide range of food additives, diet nutrients and pharmaceutical agents.

Microencapsulated rosemary (Rosmarinus officinalis) essential oil as a biopreservative in Minas frescal cheese.

Abstract: The objective of this study was to evaluate the effect of rosemary essential oil encapsulation using whey protein isolate (WPI) and inulin as encapsulation matrix on the shelf-life extension of Minas frescal cheese. Essential oil in bulk and microencapsulated forms were added to cheese at concentrations of 0.5% and compared with control treatment (cheese without rosemary essential oil). The aerobic mesophilic microorganism counting cheese with added microencapsulated rosemary essential oil was lesser than that in cheese subjected to other treatments, thus implying that microencapsulated oil has antimicrobial effects. Microencapsulated rosemary essential oil enabled a microbial reduction of 1.36 log cycles after 3 days of storage and 0.73 log cycles after 15 days of storage compared to the control treatment. The microencapsulation process did not alter the chemical composition of the rosemary essential oil and was effective in controlling the acidity of the cheese. Therefore, rosemary essential oil can be used as a potential biopreservative in cheese. Practical Applications Microencapsulation by spray-drying process maintained the original profile of the bulk rosemary essential oil and the drying process did not alter the oil chemical profile; thus, microencapsulated oil is emerging as a useful alternative for application in the food industry. Essential oil in bulk and microencapsulated forms were added to cheese at concentrations of 0.5% and compared with control treatment (cheese without rosemary essential oil). Microencapsulated rosemary essential oil was able to control the proliferation of mesophilic bacteria in Minas frescal cheese, promoting a delay in the microorganism growth during storage, thereby extending the product shelf life. Thus, the findings of our study show that microencapsulated rosemary essential oil can be used as a potential biopreservative in Minas frescal cheese.