Showing papers in "Food and Bioprocess Technology in 2019"

Application of Reinforced ZnO Nanoparticle-Incorporated Gelatin Bionanocomposite Film with Chitosan Nanofiber for Packaging of Chicken Fillet and Cheese as Food Models

Abstract: The food packaging industry has shown increasing attention toward biodegradable active packaging because of consumer demand for the extended shelf life of food products, as well as environmental concerns. In this study, the gelatin-based nanocomposite containing chitosan nanofiber (CHINF) and ZnO nanoparticles (ZnONPs) were fabricated and characterized by SEM analysis. The fabricated nanocomposite film revealed high antibacterial activity against foodborne pathogenic bacteria. To assess the efficiency of this bionanocomposite film for food packaging, chicken fillet and cheese was selected as food models. The results showed that the wrapping with nanocomposite film significantly (p < 0.05) decreased the growth of inoculation bacteria in chicken fillet and cheese samples. The changes in pH values and color parameters in chicken fillet and cheese samples were controlled by wrapping with nanocomposite film during storage time. At the end of 12-day storage, the weight loss of the wrapped chicken fillet and cheese samples with nanocomposite were 18.91 ± 1.96 and 36.11 ± 3.74%, respectively. In addition, the organoleptic characteristics of wrapped chicken fillet and cheese samples with nanocomposite film were acceptable until the end of storage. In conclusion, the fabricated nanocomposite can be suggested as a suitable packaging material for poultry meat and cheese to improve their shelf life and quality.

Assessing the 3D Printing Precision and Texture Properties of Brown Rice Induced by Infill Levels and Printing Variables

Abstract: Three-dimensional (3D) printing is an emerging technology that can be applied to processing of wide range of food products. The aim of this paper was to assess the printability of brown rice and evaluate the effects of the three variables: nozzle size (0.84 mm, 1.20 mm, 1.56 mm), perimeters (3, 5, 7), and infill densities (15%, 45%, 75%) on the quality attributes of 3D printed samples. The dimensional properties, height and diameter, were used to evaluate the printing precision, and the texture properties were assessed as hardness and gumminess. Results indicated that the printed samples matched the designed one reasonably well with some deviations in dimension induced by the three variables. The nozzle size and perimeters both have effects on the dimensional properties of 3D printed samples, and the infill density has no effect on that. With the decrease of nozzle size from 1.56 to 0.84 mm, both height and diameter of printed samples are more closely to the designed ones, which means smaller size of nozzle has a good performance on the dimensional properties of 3D printed samples. The texture properties (hardness and gumminess) were strongly related to infill density, followed by perimeters and nozzle size, while the nozzle size was thought to not only change the void rate, but also change the number of layers deposited which indirectly affected the texture characteristics. Besides, the printing time can be reduced a lot due to the decrease of void rate, which suggests a good way to improve the efficiency of printing and reduce the hardness through creating internal structure.

Influence of Drying Methods on the Antibacterial, Antioxidant and Essential Oil Volatile Composition of Herbs: a Review

Abstract: Drying is considered as the most common and fundamental technique for the postharvest preservation of herbs and is regarded as a good process to retain bioactive compounds. Past studies suggest that the choice of drying method and the parameters applied were able to influence the chemical and biological activities of herbs because pronounced differences in chemical content and composition were observed between the different drying methods. This has warranted numerous studies over the years to determine the influence of various drying methods on the content of bioactive compounds in functional food. However, reviews on the impact of drying on the bioactivity of dried herbs are rather scarce. Additionally, the influence of drying methods on the antibacterial activity of herbs has yet to be reviewed. Therefore, this paper attempts to provide a critical review on the influence of current drying process technology on the antibacterial and antioxidant properties, as well as the essential oil content, of various herbs. The use of innovative, new or existing drying technologies in preserving the active compounds was included in this paper. It was found that (i) no single drying method can be effectively used for the dehydration of all herbs; (ii) heat treatment can lead to biochemical changes (Maillard reaction), which increases the antibacterial activity; and (iii) innovative combined drying methods are promising in the production of herbs with high antioxidant activity and higher yields of total volatile concentrations.

Spontaneous Color Change of 3D Printed Healthy Food Product over Time after Printing as a Novel Application for 4D Food Printing

Abstract: A four-dimensional healthy food product was fabricated, in which 3D printed anthocyanin-potato starch (PS) gel changed its color over time to an attractive color (the 4th dimension). The color changed not only when sprayed the 3D product with different pH solutions but also independently as a response to an internal pH stimulus from another part inside the printed multi-material product. To achieve this, two parts of the gel system were combined, one part was from anthocyanin-PS gel and another part from lemon juice gel. In addition, the color change of anthocyanin-PS gel was also assessed after spraying with different pH solutions at different concentrations of PS and anthocyanin. Color changes were evaluated in terms of lightness (L*), redness (a*), and blueness (b*) using a colorimeter. The color stability of the 4D food product was examined for 24 h after printing. Moreover, a sensory evaluation test was performed to assess the consumer acceptance of the 4D food product. The printed samples sprayed with pH solutions 2, 2.5, 3, and 3.5 showed significant differences (p ≤ 0.05) in color at all PS and anthocyanin concentrations. However, pH samples 4, 4.5, and 5 did not show any visible difference in color after treatment compared to control samples. Furthermore, the color of the 3D printed anthocyanin-PS gel in model (A) gradually changed from purple to red over time during and after the printing process. On the contrary, the 3D printed anthocyanin-PS gel in model (B) did not show any noticeable color change over time after printing. This paper presents a novel application for 4D printing in the food field, which is very important for the food industry to fabricate a healthy product with attractive colors.

3D Extrusion Printing and Post-Processing of Fibre-Rich Snack from Indigenous Composite Flour

Abstract: This study focused on developing nutritious 3D-printed snacks from composite flour prepared from barnyard millet, green gram, fried gram, and ajwain seeds. The work evaluated extrusion printability of the high-fibre, high-protein composite flour. Optimised process parameters that gave best resolution and stability are nozzle diameter of 0.84 mm, nozzle height of 0.63 mm, printing speed of 2400 mm/min, extruder motor speed of 300 rpm, and movement speed of X/Y and Z axis of 6000 mm/min and 1000 mm/min, respectively. 3D-printed objects were post-processed by deep frying, hot-air drying followed by deep frying and microwave drying. With proximate analysis of the post-processed 3D-printed foods, we conclude that microwave drying could better retain nutrients, while ensuring minimal changes in colour and textural properties, as compared with other post-processing methods. All post-processed samples were acceptable in terms of sensory attributes; the developed snack has the potential to be commercialised. This work explains the successful development of nutritious 3D-printed snacks from diverse plant sources, importantly, with emphasis on the development of high-fibre foods with good consumer acceptance.

Cold Plasma Effects on Functional Compounds of Siriguela Juice

Abstract: The effects of glow discharge plasma on siriguela (purple mombin) juice quality were investigated through an experimental design changing the processing time (5–15 min) and the nitrogen gas flow rate (10–30 mL/min). Selected physicochemical properties and bioactive compounds were evaluated pre- and post-processing. No significant changes were found for vitamin C, and the processing did not affect the color of the product. Pigments, total phenolics, antioxidant activity, and B vitamins were increased due to the plasma processing. An increase in antioxidant activity was also observed. Polyphenol oxidase activity showed a decrease of about 20% (20 mL/min of N2/15 min), whereas peroxidase presented a slight activation (6%) in some processing conditions. The plasma processing imparted a positive or an adverse effect on the bioactive compounds in siriguela juice showing the importance of the optimization of food processing by cold plasma for real application. This behavior is related to the time intensity of the treatment, which can promote the extraction of the bioactive compound from the juice pulp followed by degradation at higher times or processing intensity. Due to the low pH of siriguela juice, no microbial contamination was found in the processed juices.

A Novel Approach to Enhance Blueberry Quality During Storage Using Cold Plasma at Atmospheric Air Pressure

Abstract: Blueberry is an important health food, as it contains vitamins, anthocyanins, and antioxidative enzymes. However, post-harvest life of this fruit is very short, and its quality (in terms of microbial growth, antioxidant value, and decay rate) deteriorates rapidly during storage. In this work, air cold plasma at atmospheric pressure was evaluated as a pre-treatment approach for prolonging the shelf life and improving the quality of blueberries. After plasma treatment for 10 min, the number of bacteria and fungi decreased by 93.0% and 25.8%, respectively, which might be due to the increases in DNA damage and guanine oxidation. Accordingly, the blueberry decay rates reduced by 17.7%, 14.3%, and 5.2% in the plasma treatment groups of 6, 8, and 10 min, respectively, after 20 days of storage. Interestingly, the contents of sugar, vitamin C, and total anthocyanin as well as the superoxide dismutase activity level showed the maximum increases of 1.5-fold, 1.5-fold, 2.2-fold, and 79.3%, respectively, following different plasma discharge treatments and storage times compared with those in the control groups. Furthermore, in the treated samples, the degradation times for these four parameters to decrease to control levels were longer compared to the samples without treatment. These results indicated that air cold plasma at atmospheric pressure has excellent potential as a method for enhancing the quality and shelf life of fresh produce in the food industry.

The Effects of Cold Plasma-Activated Water Treatment on the Microbial Growth and Antioxidant Properties of Fresh-Cut Pears

Abstract: Herein, we examined the effects of plasma-activated water (PAW) treatment on the native microflora survival, quality maintenance, and antioxidant activity of fresh-cut pears, which were washed with PAW under three different conditions (peak voltage = 6, 8, and 10 kV) for 5 min and then stored at 4 °C for 12 days. Distilled water and sodium hypochlorite treatment were used as control and comparison, respectively. Results showed that all PAW treatments significantly inhibited the growth of aerobic bacteria, yeast, and mold during storage, with the 8-kV PAW treatment maintaining the lowest growth rate. Additionally, no significant change was observed in the soluble solid content and titratable acidy of fresh-cut pears treated with PAW. Treatment by 6-kV PAW significantly slowed down the softening of fresh-cut pears, while the 8-kV PAW treatment significantly reduced the mass loss and the total phenolic content (P 0.05). Furthermore, PAW outperformed sodium hypochlorite in antimicrobial effectiveness and quality maintenance. Taken together, these results suggest that PAW treatment might be a promising strategy to control microbial growth and maintain the quality of fresh-cut pears.

3D Printing Complex Egg White Protein Objects: Properties and Optimization

Abstract: Three-dimensional (3D) is an emerging technique for the production of various unique and complex food items. Printing materials and recipes should be optimized to improve the quality and efficiency of 3D printing. This paper presents the development of a novel food formulation for 3D printing. This formulation is based on a complex mixture system that comprises egg white protein (EWP), gelatin, cornstarch, and sucrose. The effects of EWP addition on the rheological, lubrication, and texture properties and the microstructure of the mixture system were investigated. The results of the rheological and tribology studies show that a 5.0% (w/w) EWP mixture system is ideal for use in 3D printing. The addition of a certain concentration of EWP could improve the hardness and springiness of gel samples. The improvement in these properties facilitates the timely flow-out of the printing material from the nozzle and improves the viscosity of the printing material. The latter effect helps maintain the shape of the printing material during printing. Furthermore, the printing parameters for the optimal geometric accuracy and dimensions of the printed mixture system were determined and are 1.0 mm nozzle diameter, 70 mm/s nozzle moving speed, and 0.004 cm3/s extrusion rate. This work suggests that 3D printing based on the EWP complex system is a promising method for producing food objects with complex shapes.

Impact of Exogenous Melatonin Application on Chilling Injury in Tomato Fruits During Cold Storage

Abstract: In this study, the mechanism recruited by exogenous melatonin application at 100 μM for alleviating chilling injury in tomato fruits during cold storage was investigated. Alleviating chilling injury in tomato fruits in response to exogenous melatonin application at 100 μM may ascribe to providing sufficient intracellular ATP occur by higher H-ATPase, Ca-ATPase, cytochrome c oxidase (CCO), and succinate dehydrogenase (SDH) enzymes activity during cold storage. Also, higher unsaturated/saturated fatty acids (unSFA/SFA) ratio owing to higher linoleic and linolenic acids accumulation coincides with lower palmitic, stearic and oleic acids accumulation may be responsible for alleviating chilling injury in tomato fruits in response to exogenous melatonin application at 100 μM, which may occur by higher fatty acid desaturase 3 and 7 (FAD3 and FAD7) genes expression accompanying by lower phospholipase D (PLD) and lipoxygenase (LOX) genes expression and enzymes activity, in addition to providing sufficient intracellular ATP. Therefore, exogenous melatonin application may be a beneficial postharvest procedure for alleviating chilling injury in tomato fruits during cold storage.

Deoxynivalenol Decontamination in Raw and Germinating Barley Treated by Plasma-Activated Water and Intense Pulsed Light

Abstract: The contamination of barley kernel by Fusarium fungi constitutes a serious problem for malting-related industries. Deoxynivalenol (DON) is a secondary metabolite produced by Fusarium fungi. DON can affect dopaminergic receptors in the human brain; it may cause symptoms such as vomiting, diarrhea, headache, and fever. The aims of this study were to evaluate the DON destruction effect of the intense pulsed light (IPL) and plasma-activated water (PAW) treatments in raw and germinating barley and assess the feasibility for disinfection in the malt industry. Both non-thermal methods degraded DON concentration in germinating barley. IPL treatment significantly reduced (p < 0.05) the DON level of germinating barley samples by 35.5% after 180 pulses in 60 s, and the PAW treatment effectively degraded the DON level by 34.6% in germinating barley in the first 5 min. However, higher barley quality remained for PAW treatment (germination rate: 81–100%) than for the IPL treatment (germination rate: 41–60%). For the raw barley samples, although significant reduction (30.9%) was achieved after 180 pulses of IPL treatment, noticeable quality (germination rate: 20–40%) alteration was observed. Significantly less DON degradation was achieved by the PAW treatment on raw barley than the germinating barley for all times. Overall, these findings suggested that PAW and IPL might potentially be used to reduce DON levels in some malt-related industry applications, and PAW was recommended as a better method than IPL to maintain the barley quality.

Combined LF-NMR and Artificial Intelligence for Continuous Real-Time Monitoring of Carrot in Microwave Vacuum Drying

Abstract: In this paper, intelligent technology of combined low field NMR (LF-NMR) and back propagation artificial neural network (BP-ANN) was used to monitor moisture content in carrot during microwave vacuum drying. The relationship between different drying powers (200, 300, and 400 W) and NMR signals (A21, A22, A23, and Atotal) was investigated. Results show that as the drying time elapsed, the NMR signals of Atotal and A23 decrease all drying conditions, A21 and A22 tend to increase at high moisture content and then decrease, which is consistent with the state of water while changes during drying. NMR signals can be used as indicators for online monitoring of moisture and control of the drying process. With NMR signals as input variables, a BP-ANN model was built optimized by transfer function, training function, and the number of neurons to model the moisture content (output). Compared with a linear regression model and multiple linear regression model, the BP-ANN model with the topology of 4-25-1, transfer function of tansig and purelin, and training function of trainlm outperformed the fitting performance and accuracy. This shows that the combined approach of utilizing LF-NMR and BP-ANN has great potential in intelligent online monitoring and control applications for carrot drying.

Ultrasound Pretreatment to Enhance Drying Kinetics of Kiwifruit (Actinidia deliciosa) Slices: Pros and Cons

Abstract: The effects of ultrasound (US) pretreatment on drying kinetics and quality attributes including phenols and ascorbic acid content, color parameters (L*, a*, b*, ∆E, BI, and H°), and rehydration kinetics of kiwifruit slices were investigated. Microstructure observations of raw and US pretreated samples were also performed. Results revealed that US pretreatment reduced drying time of kiwifruit slices by 16.67–25.00% compared with the untreated samples. Weibull distribution model could precisely fit the drying behavior of samples under different treatments (R2 > 0.99). US pretreatment had a positive effect on phenolic compounds preservation but had a negative influence on ascorbic acid and solid retention. The highest loss of ascorbic acid was 40.69% after US pretreatment and 87.71% after drying compared to the content of fresh ones. Color change of kiwifruit slices was mainly caused by drying. Page model adequately predicted the rehydration characteristics of dried samples under all conditions. Microstructure observations explained why US pretreatment increased the moisture diffusion ratio and reduced the rehydration time. The findings in current work indicate that although US pretreatment can enhance drying process, it is not an ideal method for kiwifruit slices due to high loss of water-soluble nutrients.

Fabrication of Gel-Like Emulsions with Whey Protein Isolate Using Microfluidization: Rheological Properties and 3D Printing Performance

Abstract: A gel-like emulsion stabilized with whey protein was prepared by microfluidization, and the effects of the oil phase fraction on the physical properties of emulsions were studied. The rheological analysis indicated that these emulsions exhibited thixotropic behavior, and their apparent viscosity and solid-like behavior increased with increasing oil fraction from 0.3 to 0.6 (v/v). The microstructures, droplet size distribution, and thermal stability of these emulsions were also characterized using a light microscope, dynamic light scattering (DLS), and differential scanning calorimetry (DSC), respectively. The viscosity of these emulsions increased in an exponential way versus increasing oil fraction and showed good correlation coefficient (R2 > 0.99). The size of droplets in the emulsion increased from 301 ± 3.6 to 597 ± 7.3 nm. The DSC results showed that the crystalline peak of these emulsions gradually decreased from − 15 to − 21 °C and started thawing at ~ 3 °C. Visually, the textures of these emulsions could be transformed from flexible to rigid by changing the oil fraction, which suggests they could have multiple potential applications. Finally, the semi-solid emulsions were fabricated into delicate shapes using extrusion-based 3D food printing. Based on the results obtained, these emulsions may have the potential to be used as a solid-like fat substitute, which could be used in various applications such as cake decoration or customized functional foods.

Pea Protein Nanoemulsion and Nanocomplex as Carriers for Protection of Cholecalciferol (Vitamin D3)

Abstract: Pea protein is one of the few hypoallergenic vegetable proteins without genetic modification issues. Pea protein isolate (PPI) is a natural emulsifier with high nutritional value. Nevertheless, PPI’s applications in foods are limited by its relatively poor solubility and functional properties. This study was performed to explore the use of a pH-shifting and sonication combined treatment to modify the functional properties of PPI and use the soluble pea protein nanoaggregates produced by the method as base materials to form nanoemulsion and nanocomplex. The ability of these nanocarriers to protect cholecalciferol (vitamin D3) against UV radiation was examined. The stability of nanostructures during storage, antioxidant capacity, and in vitro digestion was evaluated. Generally, the modified PPI-prepared nanoemulsions over-performed the nanocomplexes in all experiments and both showed good protection of vitamin D3 against UV radiation. The stability of the pea protein nanostructures was confirmed in 30-day storage. An improved antioxidant capacity was observed in the ultrasound-treated pea proteins. The modified PPI-prepared nanoemulsions exhibited a significantly higher recovery of vitamin D3 in micelles through in vitro digestion. Therefore, the modified PPI-prepared nanoemulsion may be used as a good natural carrier for protection and delivery of health-promoting compounds in foods.

Optimization of Pulsed Electric Fields-Assisted Extraction of Polyphenols from Potato Peels Using Response Surface Methodology

Abstract: In this work, optimal pulsed electric fields-assisted extraction conditions were selected in order to intensify the extractability of polyphenol compounds with high antioxidant activity from potato peels. Effectiveness of PEF as cell disintegration technique was confirmed using both impedance measurements and scanning electron microscopy (SEM). Solid-liquid extraction (SLE) for both untreated and PEF pre-treated potato peels was optimized to determine the most effective solvent concentration (0–100% ethanol in water) as well as extraction temperature (20–50 °C) and time (30–240 min) using response surface methodology. Total phenolic compounds (TPC) and antioxidant activity (DPPH) of the extracts were determined. Results showed that the application of PEF prior to SLE has the potential to reduce duration, temperature, and consumption of solvent to achieve the same recovery yield of phenolic compounds. Under optimized conditions (54% ethanol, 233 min, and 50 °C for SLE; 52% ethanol, 230 min, and 50 °C for PEF), the extracts obtained from PEF pre-treated samples showed higher total phenolics yield (10%) and antioxidant activity (9%) as compared to the control extraction. Finally, HPLC-DAD analysis revealed the major classes of the detected polyphenolic compounds as chlorogenic, caffeic, syringic, protocatechuic, and p-coumaric acids, and no significant degradation of individual polyphenols due to PEF application was observed.

Pulsed Electric Field as an Alternative Pre-treatment for Drying to Enhance Polyphenol Extraction from Fresh Tea Leaves

Abstract: Drying is an essential pre-treatment prior to extraction of tea polyphenols from tea leaves, which is a time and energy-intensive process. In this study, pulsed electric field (PEF) was utilized to replace the conventional thermal dehydration procedure before the phenolic extraction. The influence of different PEF conditions on total polyphenol yield from fresh tea leaves combined with a solid-liquid extraction were compared. PEF treatment at 1.00 kV/cm electric field strength, 100 pulses of 100 μs pulse duration, and 5 s pulse repetition, which delivered 22 kJ/kg and induced 1.5 °C of temperature increase, was used for further study on the extraction kinetics of green tea catechins. The results indicated that compared to oven drying, PEF pre-treatment increased the extraction rate by approximately two times, without significantly altering the phenolic profiles, as revealed by using liquid chromatography combined with mass spectrometry. Scanning electron microscopy imaging revealed that PEF pre-treatment induced the formation of inhomogeneously distributed pores and protuberances on the surface of leaf tissues, which might facilitate the penetration of extraction solvent and the migration of phenolics. This study demonstrates that PEF as a time and energy efficient processing method is a promising alternative for the conventional drying process before further tea polyphenol extraction.

Online Low-field Nuclear Magnetic Resonance (LF-NMR) and Magnetic Resonance Imaging (MRI) for Food Quality Optimization in Food Processing

Abstract: Low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) have been accepted widely as a non-destructive analytical technique in food processing technology due to their sensitivity, non-invasiveness, rapidness, and cost-effectiveness. Moreover, the ability to provide real-time information on products during and after processing has been linked to the use of these analytical techniques. Timely information on quality parameters in food processing provided by online monitoring using LF-NMR and MRI may increase the quality of the product, improve operation process, and enhance production economy in food field. In this review, the use of online LF-NMR and MRI in food processing techniques, such as drying, brining and freezing, frying, fermentation, and internal quality analysis, is explored. Limitations and need for further development are outlined.

Rheological Analysis of Wheat Flour Dough as Influenced by Grape Peels of Different Particle Sizes and Addition Levels

Abstract: The present study was undertaken to assess the effects generated by grape peels flour (GPF), as a source of dietary fibers, on the white wheat flour (WF) dough rheological behavior. Dynamic and empirical rheological measurements were carried out in order to study the viscoelasticity of GPF-enriched wheat flour-based dough matrices and to identify the main actions of GPF particle size (large, medium, and small) at replacement levels from 0% up to 9%. The water competition of GPF is explained by different water binding and gelling capacities, synergistic and/or antagonistic effects of GPF compounds on the major rheological properties. Power low and Burgers models were successfully fitted with the dynamic oscillatory and creep-recovery data being suitable to interpret viscoelastic behavior of dough. Composite flour dough with smaller particle size presented higher G′ and G″ values at addition level above 5% GPF, exhibiting higher viscous component with concomitantly higher peak viscosity. Creep-recovery tests for samples with small particle size at 5% addition level showed that the elasticity and the recoverable proportion was higher compared to the rest of GPF formulations and control sample. Significant correlations (p < 0.05) were found between several parameters determined by both dynamic and empirical rheological measurements which have essential roles in monitoring GPF-enriched wheat flour dough in a wide set of different kinds of samples. This information could be helpful to optimize the particle size and addition level of GPF that could be useful to produce GPF-enriched designed bread.

Assessment of a healthy oil combination structured in ethyl cellulose and beeswax oleogels as animal fat replacers in low-fat, PUFA-enriched pork burgers

Abstract: The present work evaluates the suitability of ethyl cellulose and beeswax oleogels prepared with a healthy lipid mixture (olive, linseed, and fish oils) as fat replacers for fresh meat product development. The texture, color, thermal properties, and fatty acid composition of the oleogels indicated their suitability for the intended use, and they were stable for at least 1 month of chilled storage (3 ± 1 °C). However, the oleogels suffered some lipid oxidation during refrigerated storage, especially in the case of ethyl cellulose. Low-fat pork burgers formulated with total substitution of pork backfat by the oleogels developed were softer and without important changes in optical properties, as compared to the control. Although some lipid oxidation was observed, especially when ethyl cellulose oleogel was used, the fatty acid profile of the reformulated burgers was significantly improved, with a 3.6-fold increase of the PUFA/SFA ratio and a 23-fold decrease of the n-6/n-3 ratio, as compared to the control. A sensory acceptability test showed high ratings for the burgers made with beeswax oleogel, in contrast to the ones made with ethyl cellulose, which scored values below the neutral point. Results from this work indicate the potential of the ingredients developed for the formulation of healthier fresh meat products with an improved fatty acid profile, and the need for research on strategies to improve oxidative stability and sensory properties.

Effect of L-Arginine on Maintaining Storage Quality of the White Button Mushroom ( Agaricus bisporus )

Abstract: Decreased postharvest quality is one of the main reasons for the short shelf life of the white button mushroom. The effects of L-arginine on color, weight loss, firmness, electrolyte leakage rate, malondialdehyde (MDA) content, PPO activity, PAL activity, SOD activity, POD activity, total phenolic levels, flavonoid amounts, total sugar, and soluble protein amounts in white button mushrooms were assessed during storage at 4 °C for 8 days. The results showed that treatment with 10 mM L-arginine maintained tissue firmness, reduced electrolyte leakage, and delayed browning compared with the control treatment. In addition, 10 mM L-arginine treatment inhibited PPO and PAL activities, while inducing SOD and POD activities. Furthermore, L-arginine treatment increased the accumulation of phenolic substances and flavonoids, while total sugar and soluble protein contents were maintained at high levels throughout the storage period. These findings suggested that 10 mM L-arginine treatment may maintain the quality of the button mushrooms and extend their shelf life.

Stability of Hibiscus Extract Encapsulated by Ionic Gelation Incorporated in Yogurt

Abstract: Encapsulation techniques can protect active components from degradation during storage while maintaining their functionality. The purpose of this study was to evaluate the use of double emulsion followed by ionic gelation in the encapsulation of the extract of Hibiscus sabdariffa L. anthocyanin (HE) in the application of the microparticles in a yogurt food matrix. The ionic gelation methods used were dripping-extrusion—D (Encapsulator Buchi B-390)—and atomization—A (Spray Dryer Buchi B-290). Double emulsion (HE/rapeseed oil/pectin) and a cross-linked solution (CaCl2) were employed. Yogurt matrix was characterized for total dry matter, total lipids, protein content, total lactic bacteria, pH/acidity, phenolic compounds (Folin-Ciocalteu), total anthocyanins (differential pH), antioxidant activity (DPPH), color (colorimeter), and morphology (optical microscopy) and was subjected to a sensory appearance acceptability test (80 panelists). The samples were stored in the absence of light (5 ± 1 °C) and monitored every 7 days for total polyphenols, total anthocyanins, color, pH/acidity, and syneresis, for a period of at least 30 days. The use of microparticles obtained by double emulsion followed by ionic gelation and incorporated in yogurt matrix presented technical feasibility, providing color and functionality to the product. The yogurt matrix with microparticles obtained by the atomization technique presented high acceptability of appearance. Microparticles obtained by the dripping-extrusion technique showed greater stability of anthocyanins (48%) and color (ΔE = 1.42) during the yogurt matrix shelf life.

Ultrasound Processing Alone or in Combination with Other Chemical or Physical Treatments as a Safety and Quality Preservation Strategy of Fresh and Processed Fruits and Vegetables: A Review

Abstract: Ultrasound (US) processing has emerged as a novel food preservation technology. This strategy has proved antimicrobial effects due to cavitation, which is the formation, growth, and collapse of bubbles that generate a localized mechanical and chemical energy. This technology can be applied by water so introducing it in the washing step to obtain safe fresh or fresh-cut products could be promising. The current review provides an overview of the current knowledge and recent findings on the use of US, alone or in combination with other mild physical technologies or chemical agents, to reduce microbial loads, and to better retain their quality attributes including color and texture, as well as the content of bioactive compounds such as antioxidant, phenolic compounds, or vitamins of minimally processed fruits and vegetables. As the effects of US depends on several factors related with treatment parameters, target microorganism, and matrix characteristics, further research efforts should be directed on optimizing US processes in accordance with their further application.

Production of a Functional Yogurt Powder Fortified with Nanoliposomal Vitamin D Through Spray Drying

Abstract: In recent years, the problem of vitamin D deficiency has been echoed by extensive researches. Nutritionists believe that fortification of food products through this micronutrient is the best approach to solve this problem. In this study, properties of yogurt powders fortified with nano-liposomal encapsulated vitamin D were evaluated. The Taguchi method was deployed to design the treatments (16 runs) with 5 independent variables including temperature (160–190 °C), milk protein concentrate (0–3%w/w), modified starch content (0–3%w/w), gum Arabic (0–3%w/w) and maltodextrin (10–25%w/w), each at 4 levels. Dependent variables comprised of moisture content, solubility, colour and production (drying) yield. Analysis of our data revealed that the contribution order of different independent variables on responses was as follows: milk protein concentrate (30%), modified starch (28%), maltodextrin (22%), temperature (17%) and gum Arabic (3%). The average particle size of nano-liposomes containing vitamin D was about 120 nm. Also, SEM micrographs showed that addition of maltodextrin caused spherical powder particles with an even distribution in the matrix including yogurt and drying aids while incorporating milk protein concentrate, gum Arabic and modified starch brought about shrinkage as well as unevenness in the shape and size of powder particles.

Microencapsulation of Garlic Extract by Complex Coacervation Using Whey Protein Isolate/Chitosan and Gum Arabic/Chitosan as Wall Materials: Influence of Anionic Biopolymers on the Physicochemical and Structural Properties of Microparticles

Abstract: The aim of this study was to encapsulate garlic extract by complex coacervation method using whey protein isolate (WPI)/chitosan (CH) and gum Arabic (GA)/CH as wall materials. Two anionic biopolymers (GA and WPI) were used to find the most suitable wall materials to interact electrostatically with cationic CH. The complex coacervates were freeze-dried to obtain microparticles powders. The microparticles were examined for the nitrogen adsorption/desorption, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), sorption isotherms, zeta potential, antioxidant activity, total phenolic content, solubility, moisture content, hygroscopicity, size distribution, and water activity. X-ray diffractograms evidenced microparticles with amorphous structure. WPI/CH and GA/CH microparticles showed surface area of 2.23 and 2.40 m2 g−1 and mean pore diameter of 5.20 and 5.37 nm, respectively. The nitrogen adsorption/desorption assay showed that microparticles presented mesopores and macropores that resulted in quick completion of microparticles surface monolayer with nitrogen. The sorption characteristics of microparticles followed the type II isotherm and Guggenheim-Anderson-de Boer (GAB) model was the best model to fit the experimental data. FTIR spectrum of microparticles reveals physical interactions between garlic compounds and functional groups of wall materials, indicating that garlic compounds were intact and encapsulated. TGA results indicated that the wall materials were effective in protecting the garlic sensitive compounds. The negative carboxyl groups (–COO−) of GA were better than WPI for coacervation with positive amino groups (NH3+) of chitosan in terms of less hygroscopicity, smaller particle size, and higher retention of garlic phenolic compounds.

Improved Postharvest Quality of Cold Stored Blueberry by Edible Coating Based on Composite Gum Arabic/Roselle Extract

Abstract: The present work aimed at evaluating the efficacy of gum Arabic–based edible coating enriched with red and white roselle extracts, on the postharvest quality of blueberry fruits during storage at 4 ± 0.5 °C. Physicochemical, phytochemicals, antioxidant capability, decay percent, and microbiological analyses of coated and uncoated blueberries were performed. The change rates of polyphenol oxidase (PPO) and guaiacol peroxidase (POD) activity were also measured. The coatings (gum Arabic with or without roselle extract) inhibited the growth of microbes (yeast and mesophilic aerobic bacteria) and enzyme activities (POD and PPO) of blueberries, reduced the degradation of anthocyanins and total phenolic as well as the weight loss and decay, and improved the firmness of blueberries. In comparison with gum Arabic coating, the gum Arabic enriched with roselle extract coating showed better performance on reducing microbes, enzyme activities, and anthocyanins degradation while enhancing the total phenolic content and decreasing the decay percentage. No significant differences were observed between the coated and uncoated blueberries in terms of their antioxidant capacities and pH values (p > 0.05). In conclusion, the combination of gum Arabic and roselle extract as edible coating materials can be used to conserve the quality of blueberry.

Spray Drying Encapsulation of Elderberry Extract and Evaluating the Release and Stability of Phenolic Compounds in Encapsulated Powders

Abstract: Elderberry (Sambucus nigra L.), rich in polyphenols, has recently attracted great interest in functional food, nutraceutical, and pharmaceutical industries, due to their potential health benefits to humans. However, polyphenols are very sensitive compounds and unstable. The utilisation of encapsulated polyphenols, instead of free compounds, can overcome some of their limitations. The extraction of the polyphenols from the elderberry flowers and stems was made, followed by the microencapsulation of the extract by a spray drying process. The microparticles were characterised by size, morphology, and release profile. The microencapsulated polyphenols were completely released, with total release times that range from 600 to 1140 s. The kinetic models that have a better adjustment to the practical results are the zero order, the Korsmeyer-Peppas, and the Weibull models, with correlation coefficients that range from 0.900 to 0.999. The encapsulation efficiency was similar for all the analysed particles, being the results located in a range from 92.3 to 99.8%. After 8 months of storage, the microparticles were revaluated, being possible to conclude that the elderberry microparticles present very similar release profiles comparing with the ones obtained with fresh microparticles, which proves the successful encapsulation of the elderberry extract and the stability of the microparticles over time. This experimental work leads to a very successful encapsulation of elderberry extract.

Application of an Alginate–Chitosan Edible Film on Figs ( Ficus carica ): Effect on Bioactive Compounds and Antioxidant Capacity

Abstract: The main aim of this study was to evaluate the effect of the application of an alginate–chitosan (A–Ch) coating on the bioactive compounds and the antioxidant capacity of fresh figs (Ficus carica), collected at two maturity stages (referred to as stages III and IV), and stored for 15 days at 6 °C. The composition of the internal atmosphere of the figs, as well as the polyphenol content and antioxidant capacity, was analyzed at 0, 3, 6, 9, 12, and 15 days, respectively. The sensory quality of coated and uncoated figs, stored for 15 days, was also assessed. Fresh figs were used as a reference in the sensory quality evaluation. The A–Ch coating caused considerable modifications in the internal atmosphere of the figs at the two maturity stages evaluated. The ripening process was delayed as O2 was reduced and CO2 concentrations were increased. Further, the total polyphenol content of the figs and, also, identified individual polyphenols, were preserved by the application of the A–Ch coating. Anthocyanins, in particular cyanidin-3-O-rutinoside, were the most abundant bioactive compound. Uncoated figs also exhibited higher antioxidant capacity than coated figs at maturity stage III, whereas in coated figs antioxidant capacity was kept constant along storage period regardless of their maturity stage. Interestingly, the coated figs stored for 15 days at 6 °C showed a high acceptability in the sensory evaluation, being similar to fresh figs. Therefore, the A–Ch coating could be an excellent post-harvest technology useful in preserving not only the organoleptic and sensory attributes but also bioactive components of figs during storage at low temperature.

Improvement of Antioxidant Activity and Physical Stability of Chocolate Beverage Using Colloidal Cinnamon Nanoparticles

Abstract: In this study, the functionality of colloidal cinnamon nanoparticles in improving the antioxidant activity and suspension stability of a chocolate beverage formulated with two types of cocoa powder (natural and alkalised) was investigated. Cinnamon-loaded nanoparticles based on shellac and xanthan gum prepared using anti-solvent precipitation were incorporated in the chocolate beverage in multilevel proportions. The results showed that the addition of the nanoparticles improved the total phenolic content up to 40% and antioxidant activity up to 60% depending on the level of the nanoparticles added. Improvement of the physical stability of the chocolate beverage was observed regardless of the cocoa powder type. As the sedimentation index of the beverages made with alkalised and natural cocoa powders after 96 h was 5.7 and 85.7, respectively, the stabilisation effect of the nanoparticles seemed to be significantly influenced by the characteristics of the beverage raw material. The prevention of cocoa particle sedimentation was attributed to the colloidal network that originated from xanthan gum as shown by Cryo-SEM imaging or the increased viscosity of the mixture (i.e. from 2.4 to 27.7 mPa s at a shear rate of 50 s−1). Incorporation of the colloidal cinnamon nanoparticles had no significant effect on pH and a slight effect on the colour of the chocolate beverages. The formulated nanoparticles could be a promising complement to “ready-to-drink” products to enrich the bioactive content and prolong suspension stability.

The Effect of Low-Temperature Spray Drying with Dehumidified Air on Phenolic Compounds, Antioxidant Activity, and Aroma Compounds of Rapeseed Honey Powders

Abstract: The influence of low-temperature spray drying (inlet/outlet air, 75/50 °C) with the use of dehumidified air on rapeseed honey phenolics, antioxidant activity, and aroma compounds was investigated. Maltodextrin and NUTRIOSE® were used as carriers. Additionally, skimmed milk was tested as water substitute for feed solution preparation. Honey powders obtained by this method were characterized by high antioxidant activity and rich aroma. Changes in aroma profile during drying at low temperature were recognized as favorable and creating desirable fragrance of the product. In the case of 80% honey powders (20% of carrier), the investigated properties were not deteriorated comparing to pure honey before drying. Thus, this level of carrier addition can be treated as optimal from the point of view of bioactive properties retention during low-temperature spray drying. Such low carrier addition was not presented before in case of honey spray drying, and is favorable due to the perception of such product as natural. If used as food component, the dose of such honey-rich powder can be reduced comparing to traditional products containing higher amount of carrier (usually not lower than 50%).