Showing papers in "Journal of Food Processing and Preservation in 2015"

Foam Mat Drying of Food Materials: A Review

Abstract: Foam mat drying is an economical alternative to drum, spray and freeze-drying for the production of food powders. The liquid is whipped to form stable foam, and dehydrated by thermal means. The larger surface area of the foam accelerated the drying process for the rapid moisture removal from the high moisture feed. A high-quality food powder can be obtained by the proper selection of foaming method, foaming agents, foam stabilizers, time taken for foaming, suitable drying method and temperature. In this article, the basics of foam and its structure, methods of foaming, types of foaming method and stabilizing agents for the production of stable foam have been analyzed. The influence of foaming agents and foaming properties on the drying characteristics of fruit juices are also studied. This article reviewed the application of foam drying process for different food materials, the microstructure and the quality of powders obtained by using different foaming agents. Practical Application The renewed foam mat drying is considerably cheaper than freeze and spray drying for the production of fruit powders. This process can be used for large-scale production of fruit powders because of its suitability for all types of juices, rapid drying at lower temperature, retention of nutritional quality, easy reconstitution and cost-effective for producing easily reconstitutable juice powders. Fruit juice powders obtained through this process have high economic potentials over their liquid counterparts such as reduced volume or weight, reduced storage space, simpler handling and transportation, and much longer shelf life. The fruit powders obtained through this method can find applications in snacks, beverages, ice creams, bakery products, as a starter for the preparation of instant foods, pastes, etc.

Preparation and Characterization of PVA/ZnO Nanocomposite

Abstract: ZnO nanoparticles were synthesized by the sol-gel method. The nanoparticles were added to polyvinyl alcohol (PVA) biopolymer to compare the microstructural, mechanical, antibacterial and physical properties of bionanocomposite films reinforced with various loading contents (1, 3 and 5 wt %) and thicknesses (70, 100 and 130 μm). Results showed that with increasing ZnO content to 3 wt %, the tensile strength and Young’s modulus increased by 64 and 72%, respectively. The least amount of water vapor permeability was also observed in the sample containing 5 wt % ZnO nanoparticles. Moreover, the antibacterial properties of the films improved with ZnO addition and increased by increasing nanoparticle content up to 5 wt %. However, the transparency of the PVA-based films decreased by ZnO addition.

The impact of hot air drying on the physical-chemical characteristics, bioactive compounds and antioxidant activity of acerola (malphigia emarginata) residue

Abstract: This article evaluates the effect of hot air drying on the physicochemical characteristics, color, concentration of bioactive compounds and antioxidant activity of agroindustrial residue of acerola, which was hot air dried under different conditions of temperature (60, 70 and 80C) and air velocity (4, 5 and 6 m/s), taking up the residue in natura as the control group. The experimental dimensionless moisture content as a function of drying time of acerola residue is also presented and discussed. The retention values of total phenolic (26–31%), carotenoids (50–61%), anthocyanins (23–36%), proanthocyanidins (21%), ascorbic acid (40–70%) and the antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl method (20%) were calculated and discussed. Considering the concentration of bioactive compounds detected in the final product, as well as the microbiological stability achieved by the substantial moisture reduction, it can be concluded that the dried acerola residue is an important source of bioactive compounds with appropriate characteristics to be utilized as a health-relevant food ingredient. Practical Applications Brazil is one of the largest agricultural producers in the world. In recent years, the processing industry has developed and as a consequence, the generation of residues has also increased. The search for answers to this technological challenge was the motivation of this research, which evaluated the drying process as means for obtaining a natural functional powder from acerola residue. The data shown would provide the scientific rationale for a better exploitation of this tropical fruit residue.

The Effects of Storage and Preservation Technologies on the Quality of Fish Products: A Review

Abstract: The aim of this review is to give an overview of the main techniques used and the subsequent quality changes of fish from the harvest to the plate. Fish is often considered to be a difficult culinary object due to the fact that it is easily spoiled, prone to oxidation and developing off-flavors due to wrong handling. The preservation of the sensory and nutritional quality of fish is significantly influenced by several parameters. In this review, commonly used storage and preserving methods applied for fish will be presented and their effects on the general quality aspects will be highlighted. It is important to adapt the processing to the special requirements that a product, prone to bacterial spoilage and oxidation, as fish has. However, if storage techniques are combined and applied in an innovative way, products with a high-quality, good sensory properties and a beneficial nutritional value will be achieved.

FTIR, XRD and SEM Analysis of Ginger Powders with Different Size

Abstract: The grinding treatment could modify and change the chemical property of ginger powder. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to detect the chemical functional groups and structure of ginger powders with different sizes. FTIR showed that the absorption bands of different sizes of ginger powders were similar, but the intensity of bands decreased with reduce ginger particle size. The spectra of ginger superfine powder with a particle size of 8.34 μm were shifted compared with spectra of the particle sizes of 300, 149, 74 and 37 μm. It was concluded that the rigid and ordered structure of the cellulose was deteriorated by the superfine grinding treatment. XRD revealed that as the powder size decreased, the crystallinity and intensity of crystal peaks increased. The results of SEM showed that the superfine pulverizing was effective to change the original structure of the ginger powders. Practical Applications Superfine grinding is a novel technology in food processing and can improve the physicochemical properties of food materials. In addition, the knowledge provided by this work may promote the application of superfine grinding in the food industry.

Use of Almond Gum and Gum Arabic as Novel Edible Coating to Delay Postharvest Ripening and to Maintain Sweet Cherry (Prunus avium) Quality during Storage

Abstract: Almond gum and gum arabic were used as edible coatings for sweet cherries in order to delay their ripening during postharvest storage at 2C and 90–95% relative humidity for 15 days. Coating of sweet cherries with 10% almond gum or gum arabic has been found to enhance their shelf life and postharvest quality. Fruits coated with almond gum or gum arabic showed a significant decrease in respiration rate as well as ethylene production. Moreover, coatings were able to delay changes in weight, firmness, titratable acidity, soluble solids concentration and color development compared with uncoated control fruit. The results suggested that by using almond gum as an edible coating, we can delay the ripening process and increase the shelf life of sweet cherries stored at 2C for 15 days without any spoilage and off-flavor. Practical Applications Edible coatings could be an effective tool for delaying the ripening process of fruits and vegetables during the postharvest storage period. The effectiveness of almond gum from Prunus dulcis as a novel edible coating, in comparison with gum arabic, was studied in sweet cherries in order to maintain parameters related to quality during postharvest storage. The results showed that almond gum was able to slow down the gas exchange by reducing the CO2 concentration of coated sweet cherries, which reduced their ethylene production. As a result, the evolution of parameters related to the quality of sweet cherries was significantly delayed. Moreover, the results suggested that almond gum could be explored as a novel and potential natural edible coating to substitute the synthetic forms of fruit and vegetable packaging.

Decontamination and Sensory Properties of Microbiologically Contaminated Fresh Fruits and Vegetables by Microwave Plasma Processed Air (PPA)

Abstract: Currently used disinfection or sanitation methods for fresh fruits and vegetables lack antimicrobial effectiveness, but are high in costs, water consumption or chemicals One alternative could be to apply nonthermal plasma at atmospheric pressure to the described issue The experimental set-up implements microwave plasma, which generates plasma processed air (PPA) containing manifold reactive nitrogen species-based chemical and antimicrobial compounds Five different fresh produces were first contaminated with seven different microorganisms eg, bacteria, yeasts and endospores followed by a treatment with PPA The plasma was ignited for 7 s only After a post-plasma treatment time of maximum 15 min with PPA, reduction factors of microbiological load greater than 6 log were detected Furthermore, sensory examinations showed only little influences in texture, appearance and odor The characteristics of plasma and its generated cocktail of chemical compounds leads to a high microbial inactivation on various specimens and offers a wide range of possible applications Practical Applications Nonthermal atmospheric pressure plasma is a nonthermal, nontoxic and low-cost possibility to inactivate microorganisms on fresh produce surfaces It could be used in dry and wet environments and allows a treatment of fresh food and virtually every conceivable surface in batch or inline processes along the whole value chain of food production, and could be implemented as an alternative to ozone or chlorine dioxide treatment

Antioxidant Activity and Phenolic Content of Seed, Skin and Pulp Parts of 22 Grape (Vitis vinifera L.) Cultivars (4 Common and 18 Registered or Candidate for Registration)

Abstract: Total phenolic contents and antioxidant activities of pulp, seed and skin of 22 grape varieties (7 white and 15 red) grown in the Marmara region of Turkey were determined (common, registered or candidate cultivars). The total phenolic contents of grape pulp, seed and skin parts ranged from 9.26 to 62.29, from 162.29 to 326.18 and from 96.61 to 167.42 mg gallic acid equivalents/100 g fresh weight, respectively. Seasonal changes were noticeable in the total phenolic contents and antioxidant activities of different grape parts. The antioxidant activity of grape seeds of registered or candidate cultivars was the highest, followed by skins and pulps. The antioxidant activities of grape skins were higher in red varieties than in white varieties. The results indicated that registered and candidate red or white grape cultivars may have high amounts of phenolics and possess a superior antioxidant activity in comparison to popular cultivars, such as Bilecik Irikarasi, Hamburg Misketi, Alfons and Isabella. Practical Applications Grapes are an important commercial commodity because they can be consumed fresh or processed into many food products such as juice, jams, raisins and wine. Chemical properties of grapevines are one of the most important factors that determine the industrial use of grape berries. A great deal of diverse phenolic compounds is located in the skins, pulp and seeds of grapes. The antioxidant activity of different parts of grapes has been studied in popular and hybrid varieties; however, studies should also be continued on hybrid varieties to determine better grape berries with high antioxidant activity and phenolic content. Berries with better quality in terms of antioxidant activity may present great potential for the food industry as well as health-conscious consumers.

Modeling Drying Characteristics of Hawthorn Fruit under Microwave-Convective Conditions

Abstract: A laboratory microwave convection dryer was used to dry the hawthorn fruit, applying microwave power in the range of 270–630 W, air temperature in the range of 40–70C and air velocity in the range of 0.4–1.6 m/s. Five empirical drying models for describing time dependence of the moisture ratio change were fitted to experimental data and model parameters in equations were determined by multiple regression analysis. Results showed that the Midilli et al. with R2 = 0.9983, χ2 = 0.0033 and RMSE = 0.0485 had the best performance (among the five models tested) in predicting the moisture. The effective moisture diffusivity, which ranged between 9.29 × 10−10 and 8.81 × 10−9 m2/s, increased with the increase in microwave power and air temperature. The activation energy of samples was found between 12.25 and 27.90 kJ/mol. Maximum shrinkage (64.39%) was achieved at the air temperature of 70C, microwave power of 630 W and air velocity of 0.4 m/s. Practical Applications Hawthorn has been considered as an important traditional herbal medicine due to its disease prevention effects. Advantages of microwave convection drying include short processing time, high mass transfer coefficients, low energy consumption and high quality. As heat and mass transfer and quality changes during drying of hawthorn with microwave-convective method are not described in the literature, it is of importance to gather such data and compare them to find the optimum point of the process. In this study, drying kinetics of hawthorn slices at different air temperatures and microwave powers were studied. Furthermore, simple models for the simulation of drying process, taking into account the fruit shrinkage, were proposed. The results of this study will be helpful in the technological application of microwave-hot air-drying for hawthorn preservation.

Stability of Curcumin Microencapsulated by Spray and Freeze Drying in Binary and Ternary Matrices of Maltodextrin, Gum Arabic and Modified Starch

Abstract: Curcumin yellow dye is considered as an antioxidant, susceptible to light and oxidative degradation. Microencapsulation improves its stability and facilitates its use. This work aimed to investigate the effects of different formulation wall materials (gum arabic, a binary mixture of maltodextrin and modified starch, and a ternary mixture of gum arabic, maltodextrin and modified starch) and different drying methods (for spray and lyophilization) on the stability of microcapsules of turmeric oleoresin. The drying method affected retention curcumin powder in the drying process and storage of the microcapsules under incident light. Curcumin retention during lyophilization was greater than spray drying, but showed the opposite behavior during storage; spray-dried capsules had a higher retention of curcumin after 8 weeks under light exposure. As a result, the ternary mixture of gum arabic, modified starch and maltodextrin was more effective to prevent loss of curcumin and color changes in the microcapsules. Practical Applications The main function of turmeric oleoresin is to give color and tempered aroma in certain foods such as pickles and mustard. The knowledge of encapsulation techniques allows the control of the bioactive components, the release time and dosage of turmeric oleoresin in the structure of the food. Moreover, the encapsulation of oleoresin helps to reduce oxidation process by exposure to the environment, increasing the shelf life and the solubility. The results of analysis of this work lead to the use of bioactive components for implementation in similar products, thereby improving their stability.

Antioxidant and Antimicrobial Activities of Thyme and Clove Essential Oils and Application in Minced Beef

Abstract: In this study, thyme and clove essential oils (EOs) were studied for their chemical composition, antioxidant, antiradical and antibacterial activity and application in ground beef. Carvacrol (75.27%) and eugenol (75.2%) were detected by gas chromatography-mass spectrometry analysis as the main components of thyme and clove EOs, respectively. Broth microdilution method showed all bacteria inhibited by the EOs, while Shewanella putrefaciens and Listeria innocua were the most resistant bacteria to thyme and clove EOs, respectively. EO treatment restricted the growth of artificially inoculated Salmonella typhimurium and native Coliforms in the ground beef. Antioxidant activity determined by ferric-reducing antioxidant power and 1,1 diphenyl-2-picrylhydrazyl methods demonstrated that clove EO had higher in vitro antioxidant activity than thyme EO. Similar results were obtained in ground beef application using 2-thiobarbituric acid value. EOs of clove (2MIC) exerted remarkable higher antioxidant activity in ground beef than EOs of thyme (4MIC), which represent valid alternative antioxidant in meat products. Practical Applications Plant essential oils (EOs) serve as a “safe” alternative to chemical or synthetic antimicrobials and antioxidants to struggle with the foodborne pathogens or spoilage organisms, inhibiting lipid oxidation and thus extending shelf life. Antioxidant activity determined by ferric-reducing antioxidant power and 1,1 diphenyl-2-picrylhydrazyl methods showed that clove EO had higher in vitro antioxidant activity than thyme EO. Results obtained using 2-thiobarbituric acid value in ground beef application were found similar. EOs of clove (2MIC) exerted higher antioxidant activity in ground beef than EOs of thyme (4MIC). Therefore, EOs could be a valid alternative antioxidant in meat products.

Mathematical Modeling of Thin‐Layer Pineapple Drying

Abstract: The drying kinetics of pineapple was studied, and the model that best describes it was selected. Pineapple slices were dried in a hot-air oven at temperatures of 50, 60 and 70C; microwave power levels of 385, 540 and 700 W, respectively; and under direct sunlight. Drying time decreased with increase in drying temperature and power level. Drying took place entirely in the falling rate-drying period. Seven mathematical models were fitted into the experimental data. The goodness of fit was determined using the coefficient of determination (R2), reduced chi-square (χ2), root mean square error and sum square error. The two-term, parabolic and Page model best explained the hot-air, microwave and sun-drying behavior of the pineapple. The effective moisture diffusivity increased from 6.89 × 10−10 to 5.1 × 10−08 m2/s while the activation energy was 12.46 KJ/mol for oven drying and 1.54 W/g for microwave drying. Practical Applications Pineapple as a fruit is a very rich source of minerals and vitamins including potassium, manganese, copper, magnesium, vitamin C and B6, thiamine, foliate, and also dietary fiber. These mineral and vitamins are essential for proper human growth and development especially for people who live on low income in tropical developing countries. The high moisture content of pineapple, which makes it highly perishable, and its abundance during periods of harvest, gives rise to postharvest losses with attendant reduction in the availability of its minerals and vitamins. Drying, a common preservative method, can be used to reduce these postharvest losses and thus make shelf-stable products last longer. The knowledge of the drying kinetics and subsequently the selection of an appropriate thin-layer drying model can be used to predict drying times and subsequently optimize the drying process for greater efficiency.

Ozone Treatment Efficiency in Aspergillus and Penicillium Growth Inhibition and Mycotoxin Degradation of Stored Wheat Grains (Triticum aestivum L.)

Abstract: The efficacy of ozone (O3) gas treatment to inhibit the strains growth of Aspergillus flavus and Penicillium citrinum and of aflatoxin and citrinin (CTR) to degrade in wheat grains were evaluated. The tests were performed in laboratory pilot silos containing grains artificially contaminated by these fungi or mycotoxins. Briefly, the samples were divided into control groups (no O3 gas) and O3-treated groups (40 and 60 μmol/mol), which were exposed for 30, 60, 120 and 180 min. In the highest concentration of O3 exposure (60 μmol/mol), A. flavus and P. citrinum showed complete growth inhibition after 180 min. In addition, regarding the same O3 exposure, the AFB1 and AFB2 levels were significantly reduced (12.51 and 41.06 μg/kg) when compared with control (231.88 and 265.79 μg/kg). Moreover, the CTR levels were significantly decreased after O3 treatment in both concentrations (40 and 60 μmol/mol) after 180 min of O3 exposure (103.64 and 42.90 μg/kg) when compared with control group (146.85 and 173.51 μg/kg). Practical Applications The Aspergillus flavus and Penicillium citrinum strains have been found in stored wheat grains. These fungi can be responsible for aflatoxins and citrinin formation under specific temperature and humidity storage conditions. In order to overcome this problem, ozone has been studied in laboratory scale to control fungal growth. It is possible to say that this is an attractive practice and is effective for the food industry because it decomposes to molecular oxygen without leaving residues, and furthermore is considered safe by the U.S. Food and Drug Administration.

Foam‐Mat Drying of Cantaloupe (Cucumis melo): Optimization of Foaming Parameters and Investigating Drying Characteristics

Abstract: In the present study, foam-mat drying technique is used to dry cantaloupe pulp into powder. Foaming conditions, namely amount of egg white powder, xanthan gum and whipping time, optimized using response surface methodology for minimizing foam density and drainage volume. To evaluate drying behavior of the optimized foam, drying was carried out in a batch-type thin-layer dryer at three drying temperatures (40, 55 and 70C) on 3- and 5-mm thicknesses. Ten thin-layer drying models were evaluated in the kinetics research. Based on the statistic tests performed, Weibull distribution model can describe drying behavior of foams for all drying processes. Moreover, Fick's second law was employed to calculate the effective moisture diffusivity that varied from 3.283 × 10−9 to 9.483 × 10−9 m2/s and from 4.053 × 10−9 to 1.216 × 10−8 m2/s with activation energy values of 31.714 and 33.043 kJ/mol for foam thicknesses of 3 and 5 mm, respectively. Practical Applications Cantaloupe (Cucumis melo) is a popular fruit and widely consumed in the world. Cantaloupe has many potential health benefits, but it is seasonal fruit and its shelf life is limited. Moreover, cantaloupe is sensitive to high-temperature processes. Foam-mat drying is an alternative for preservation of cantaloupe in the form of dried powder using medium temperatures. Cantaloupe pulp powder have a longer shelf life and may be a suitable source of β-carotene and vitamin C. This powder, because of its ability to contribute special characteristics such as flavor, color and water-binding properties to the final product, can be used as instant beverages, ingredients for bakery or extruded cereal products, ice cream, yogurt as well as pharmaceutical tablets.

Effect of Zataria multiflora Boiss Essential Oil and Grape Seed Extract on the Shelf Life of Raw Buffalo Patty and Fate of Inoculated Listeria monocytogenes

Abstract: The present study was conducted to investigate the effect of Zataria multiflora Boiss essential oil (ZEO) and grape seed extract (GSE) on microbial and chemical changes in raw buffalo patty at a temperature of 8C. First, chemical composition and minimum inhibitory concentration of oil against Listeria monocytogenes were identified. Then, ZEO and GSE were added in raw buffalo patties and analyzed for spoilage microorganism count, lipid oxidation, pH, sensory attributes and inoculated L.monocytogenes survival at 8C for 9 days. Results revealed that samples containing 0.1 ZEO+0.2 GSE showed significant decrease in the growth of all tested microbial groups as well as the most decrease in the level of lipid oxidation at the end of storage period. Control and samples with 0.1 ZEO were the most preferred samples by sensory panelist, indicating that ZEO and GSE can be practically applied in food systems especially in meat in order to extend the shelf life. Practical Applications: Buffalo meat is highly prone to microbial and chemical spoilage as they are rich in essential nutrients and putrefying in nature. The adverse effects of various chemical preservatives caused to attract the consumer's attention to natural alternatives. Therefore, in order to increase the shelf life and quality characteristics of meat, new processing technologies and new ingredient systems that are associated with natural and organic foods are applied. These results demonstrate the potential combined use of grape seed extract and Zataria multiflora Boiss essential oil to the meat industry in the development of novel healthy meat products with improved shelf life and superior product quality. © 2015 Wiley Periodicals, Inc.

Response Surface Analysis and Process Optimization of Twin Screw Extrusion Cooking of Potato-Based Snacks

Abstract: The aim of the present study was to optimize the extrusion process for potato-based snacks using response surface modeling approach. A blend of mashed potatoes, rice and chickpea flour was used in the study. The effects of feed moisture, barrel temperature and screw speed on product responses viz. specific mechanical energy (SME), bulk density (BD), water absorption index (WAI), water solubility index (WSI) and hardness was studied using response surface methodology. The blend of potato-rice and chickpea was extruded at different moisture content (12.6–19.4%), screw speed (349–601 rpm) and barrel temperature (116–184C). Feed moisture had significant effect on all product responses, whereas screw speed and barrel temperature, both independent variables, had significant effect on SME, WSI and hardness of the product. Increase in feed moisture reduces SME and WSI and increases BD, WAI and hardness. Increase in screw speed decreases the BD, WAI and hardness of the snacks, whereas increase in barrel temperature decreases the SME, BD, WAI and hardness but increases the WSI. Optimized extrusion parameters for preparation of snacks were 14% moisture, 550 rpm screw speed, 170C temperature. Practical Applications Potatoes are generally processed into flakes, granules and flour by dehydration for using it as raw material for extrusion. Processing costs are very high, so mixing of mashed potatoes with cereal or pulse flour could be an energy-efficient way to use potatoes in extrusion. The consumers are becoming increasingly health conscious and while many admit that pulses are good for them, they are not sure how to use them in diet. There is also a perception that cooking of pulses is difficult and/or time consuming. There is need to find ways to increase consumption of pulses with little extra efforts. This paper explores the optimization of extrusion condition for development of nutritious snacks from potato-chickpea blends.

Ultrasound‐Assisted Extraction of Bioactive Compounds and Antioxidants from Carrot Pomace: A Response Surface Approach

Abstract: The phenolic compounds from carrot pomace were extracted using ultrasound-assisted extraction (UAE). A three-factor and three-level central composite design was used to evaluate the effects of the operation parameters, including extraction time (3–37 min), extraction temperature (10–60C) and ethanol concentration (13–97%) on the extraction yields of total phenols, antioxidant capacity, chlorogenic acid, caffeic acid, catechin and epicatechin. UAE optimal conditions for total phenols, total antioxidant capacity and phenolic compounds were achieved using response surface methodology. The results revealed that independent variables significantly affected the extraction yields of all the responses. A good correlation between experimental and predicted values (P > 0.05) under optimal extraction conditions suggests that the UAE is a more efficient process for the extraction of bioactive compounds from the carrot pomace. Practical Applications Ultrasound-assisted extraction of phenolic compounds from carrot pomace may successfully be employed in the industrial development because it is an eco-friendly and a time-saving process for the preparation of natural antioxidants and in turn may increase the antioxidant potential of the extracts of agro-industrial waste products of the food processing industries.

Effect of Pasteurization and Shelf Life on the Physicochemical Properties of Physalis (Physalis peruviana L.) Juice

Abstract: The main objective of this work is to evaluate the physicochemical characteristics of Physalis (Physalis peruviana L.) after pasteurization and shelf life for 21 days at 5C. Pasteurization at 90C for 2 min led to a significant improvement in the organoleptic characteristics of the juice. Pasteurization of juice reduced the ascorbic acid content from 38.90 to 30.20 mg/100 g during shelf life while fresh juice preserved this compound. Heated juice had total phenols and % DPPH (2,2- diphenyl-1-picrylhydrazyl) loss of 20.88 and 28.51%, respectively. The ratio of glucose to fructose in all evaluated juice is almost 1:1, whereas sucrose level was decreased by 25% for fresh juice and 16% for pasteurized juice. Higher negative numerical values of whiteness index were determined on Hunter's scale for the intensity of color. After pasteurization, a 7% increase in viscosity and a 22% decrease in cloud were observed after 21 days of shelf life. Practical Applications Physalis peruviana L. juice contains various active compounds with potential health benefits and hence has a potential as functional ingredients. Preservation of fruit for consumption exposes the physicochemical, color, antioxidant capacity and sensory characteristics to detrimental factors that may lead to alterations in concentrations and health-related quality. Due to the health benefits of Cape gooseberry consumed after some form of processing, it is important to investigate the effect of such treatments on the bioactive compounds that are present in the fruit. The effects of common processing conditions on the chemical composition of P. peruviana L. juice were investigated. The changes in the physicochemical properties of the samples varied with the processing treatments. These findings are important to study processing conditions, which could be applied and develop a new method in order to preserve the P. peruviana L. juice without affecting its natural contents.

Color, Chemical and Functional Properties of Plantain Cultivars and Cooking Banana Flour as Affected by Drying Method and Maturity

Abstract: Effects of drying method and maturity on color, chemical and functional properties of plantain (Agbagba and Obino L'ewai) and cooking banana flour were investigated. Generally, dried cooking bananas and plantain cultivars showed higher CIE L (60.96–84.86), lower a (0.39–9.01) and b (11.08–26.88) than fresh (undried) samples (CIE L = 62.22–70.32; a = 2.52–11.06; b = 24.5–30.02). Loose bulk density of unripe, turning and yellow ripe cooking and plantain cultivars varied from 0.459 to 0.556, 0.267 to 0.546 and 0.204 to 0.562 g/mL, while the packed bulk density varied from 0.560 to 0.668, 0.295 to 0.665 and 0.233 to 0.640 g/mL, respectively. Flour of unripe samples showed significantly higher water absorption capacity (WAC). The WAC of unripe, turning and yellow ripe cooking bananas and plantain cultivars varied from 0.98–1.69, 0.68–2.35 and 0.61–0.89 g water/g flour while oil absorption capacity ranged from 0.90 to 1.39, 1.00 to 2.41 and 1.03 to 2.65 g oil/g flour, respectively. Cyclodextrins (A and B), L(−)-glucose, D-(+) glucose, L-glyceraldehyde, α- and β-D-(+) glucose, α -D-(+) galactose, Octyl-β- D-(+) glucose were found in the flour. Practical Applications Plantains and cooking bananas are known to have high starch contents and characteristic flavors that change with acid composition during ripening. These climacteric commodities ripen rapidly, and can only be stored for a few days in the fresh form. Plantains and cooking bananas have great potentials as food, processing into shelf-stable low-moisture flour using less capital-intensive technologies reduce their postharvest losses, add value and make the commodities available all year round. Selection of the appropriate drying method and the maturity of the commodities would be necessary for the production of high-quality cooking banana and plantain flour for cottage and industrial use. Understanding of the changes during ripening and processing of these commodities is required for necessary processing actions and decisions.

Antifreeze Proteins: Characteristics, Function, Mechanism of Action, Sources and Application to Foods

Abstract: Antifreeze proteins (AFPs) are synthesized by various organisms to enable their cells to survive subzero environments. AFPs exert their effects by lowering the freezing point of water as well as preventing the growth of ice crystals and recrystallization during frozen storage. Their ability to modify the growth of ice results in the stabilization of ice crystals over a defined temperature range and in the inhibition of the recrystallization of ice, which could reduce drip loss during thawing, improve the quality and extend the shelf life of frozen food. However, the high cost of these proteins and the requirement of biotechnological methods for commercial production limit their potential use in foods. Despite these limitations relatively small amounts are sufficient to exhibit activity, which suggests AFPs as possible additives for foods in the future. This review presents the results of investigations on the characteristics, function, mechanism of action, sources and potential food uses of AFPs. Practical Applications Antifreeze proteins (AFPs) act both by lowering the freezing point of water and by inhibiting ice crystals, and prevent recrystallization during storage. Because of their advantageous characteristics in recent years, numerous studies have been made on the use of AFPs in improving the properties of frozen foods. The aim of this paper is to present the results of numerous investigations on AFPs obtained from fish, plants or insects and discuss their characteristics, function, mechanism of action, sources and potential food uses.

Effect of Methylcellulose-Based Edible Coating on Strawberry Fruit's Quality Maintenance During Storage

Abstract: Edible coatings can provide an alternative to enlarge fresh fruits' postharvest life. The effect of methylcellulose edible coating on some qualitative, chemical, physical and mechanical properties of strawberries was investigated. Coatings were used directly on the fruit surface then stored at 4C for 11 days. The results showed that no significant differences were statistically observed in total acidity, anthocyanin and antioxidant activity compared with the control ones. In contrast, the edible coating significantly prevents weight loss and decay and also, keep a small amount of fruit sugar, maintained the firmness of the strawberries, improved its quality and storage features. The cellulose coating had significant effects on surface color parameters. The color of the coated fruits was darker and clearly had less redness (lower L*, C* and H values). Practical Applications The maintenance of the quality of fresh produce is still a major challenge for the consumers. The most important quality attributes contributing to the marketability of fresh fruit include appearance, color, texture, flavor, nutritional value and microbial safety. Strawberry fruits should be firm but not crunchy. Decreased quality during postharvest handling is most often associated with water loss and decay. The postharvest life of strawberries can be extended by coating technique combined with refrigeration. Protective edible coatings are applied to fruits and vegetables as part of the postharvest treatment of fresh fruits and vegetables as a method of preservation. The purpose is to extend the shelf life of strawberries and to provide a barrier against hazards.

The Optimized Concentration and Purity of Spirulina Platensis C-Phycocyanin: A Comparative Study on Microwave-Assisted and Ultrasound-Assisted Extraction Methods

Abstract: Microwave-assisted (MAE) and ultrasound-assisted (UAE) extraction methods to efficiently extract the C-phycocyanin (C-PC) from the blue-green algae, Spirulina platensis, were compared. The results showed that the linear and interaction effects of two parameters of extraction time and buffer pH on C-PC concentration and purity ratio were significant. The C-PC concentration was enhanced by increasing extraction time up to 7 and 25 min for UAE (2.84 mg/mL) and MAE (4.54 mg/mL) processes, respectively. The extraction time significantly had more effect than the buffer pH value on the purity ratio. The highest purity ratio of C-PC in UAE (0.65) and MAE (1.27) technologies was obtained in buffer pH values of 6.0 and 7.0, respectively. The C-PC extracted from the MAE system significantly had higher concentration and purity than that obtained using the UAE procedure. Thus, MAE as an efficient method can be applied to extract heat-sensitive C-PC from S. platensis in an industrial scale. Practical Applications C-phycocyanin (C-PC) is a blue-colored photosynthetic accessory pigment in all cyanobacteria that has high antioxidant activity to enhance the prolonged induction period for fats or oils by preventing peroxidation of unsaturated fatty acids. Finding a proper and novel extraction method is necessary to obtain high-quality C-phycocyanin for using in different food formulations. Optimization of experimental conditions can thus provide selection of a fast and cost-saving process in the extraction of this functional ingredient.

Color Degradation Kinetics of Carrot (Daucus carota L.) Slices during Hot Air Drying

Abstract: The effect of temperature on color change kinetics of carrot slices was investigated during hot air drying. The color parameters for the color change of the foods were quantified by Hunter L (whiteness/darkness), a (redness/greenness) and b (yellowness/blueness) values. These values were also used for calculation of the total color change (ΔE). The color values (L, a and b) decreased, while ΔE increased during drying. Zero- and first-order kinetic models were applied to describe color change. Mathematical modeling color change kinetics indicated that both models were found to describe the L, a and b values adequately. However, ΔE followed zero-order kinetics. PRACTICAL APPLICATIONS In this study, a hot air dryer was used. The effect of air temperatures (45, 55 and 65C) on color change kinetics of carrot slices was investigated. The color of carrot slices was measured during hot air drying. Zero- and first-order kinetic models were applied color change. The first-order kinetic model adequately described evolution of L, a and b values derived for carrot slices during drying. Dried carrots are used as an ingredient in instant soups or meals and an excellent candidate for developing oil-free, healthy snack food if the nutritional value can be well preserved.

Effect of Spray Drying of Four Fruit Juices on Physicochemical, Phytochemical and Antioxidant Properties

Abstract: Fruit juices from Khasi mandarin orange, watermelon, carambola and pineapple were spray dried with 20% maltodextrin and studied for physicochemical, phytochemical and antioxidant properties. Khasi mandarin orange gave the highest yield (85.27%). Viscosity of the feed sample and the particle size distribution of the powders varied among samples. Moisture content ranged between 3.41 and 5.47%. pH was in the acidic range and titratable acidity was highest in carambola (0.70%). Solubility values ranged from 57.57 to 76.75%. Hygroscopicity of the juice powders ranged from 11.63 to 11.99 g/100 g of samples. The change in color (ΔE) after spray drying was highest in reconstituted Khasi mandarin. The phytochemical content and antioxidant activity were significantly different between the spray-dried and fresh untreated juice samples. An increase in total phenolic content, total flavonoid content, ferric reducing antioxidant potential and DPPH radical scavenging activity was observed in Khasi mandarin juice powder. Practical Applications Application of heat treatment causes number of changes in quality parameters of spray-dried fruit juice powder. The present work studied the effect of spray drying on the physicochemical properties of four fruit juice powders as well as changes in their phytochemical and antioxidant activities. It was observed that spray drying had both positive and adverse effects on the physicochemical and antioxidant properties depending on the fruit juice type. The phytochemical and antioxidant properties were enhanced upon spray drying of Khasi mandarin juice. The results indicate that spray-dried Khasi mandarin orange and watermelon juice powders can be promoted for processing by the fruit processing industries.

Effect of Ultrasound-Assisted Osmotic Dehydration Pretreatment on Drying Kinetics and Effective Moisture Diffusivity of Mirabelle Plum

Abstract: Conventional air drying of plum is a slow and energy-intensive process because of its waxy skin having low permeability to moisture. Ultrasound application in drying foodstuffs aims at reducing the time needed to process and improve the quality characteristics of dried product. In this study, the effect of ultrasound-assisted osmotic dehydration pretreatment on drying kinetics and effective moisture diffusivity of Mirabelle plum during drying was examined. Pretreatments including ultrasonication time at two levels (10 and 30 min), osmotic solution concentration at two levels (50 and 70% sucrose) and immersion time in osmotic solution at four levels (60, 120, 180 and 240 min) were performed. Results showed that application of ultrasound-assisted osmotic dehydration pretreatment can lead to a significant increase in effective moisture diffusivity (from 5.84 × 10−9 to 7.36 × 10−9 m2/s) resulting in a 20% decrease in drying time, and thus involving a higher energy saving and preserving heat labile nutrients. Practical Applications The Mirabelle plum is appreciated by consumers for its health benefits. Drying is among the most popular methods to prolong its shelf life. The Mirabelle plum's skin consists of an underlying amorphous wax layer adjacent to the cuticle proper, together with crystalline granules of wax protruding from the surface. The waxy skin has a low permeability to moisture that increases drying time leading to possible quality deteriorations. Therefore, any pretreatment for plum drying processes that decreases drying time by reducing the initial moisture content and preserves the prune (dried plum) quality is of considerable interest. Methodologies such as ultrasound-assisted osmotic dehydration can be implemented as an alternative pretreatment to reduce drying time and, consequently, processing costs. This study provides information on the effects of operating conditions (sonication time, concentration of osmotic solution and immersion time in the osmotic solution) on drying kinetics, total processing time and effective moisture diffusivity.

Quality of Tuna Fish Oils Extracted from Processing the By-Products of Three Species of Neritic Tuna Using Supercritical Carbon Dioxide

Abstract: Fatty acid constituents of total lipids extracted from the head, the skin and the viscera of three neritic tuna species, namely Thunnus tonggol, Euthynnus affinis and Auxis thazard, using supercritical carbon dioxide (SC-CO2) and Soxhlet extraction method were determined and compared. Saturated fatty acid (39.7–48.5%) was dominant in conjunction with monounsaturated fatty acid (21.9–26.6%) and polyunsaturated fatty acid (PUFA) (24.1–27.9%) in all species, and the difference between methods were nonsignificant. Docosahexaenoic acid was the major PUFA, accounting for 17.0–19.9% in the head, 15.7–17.3% in the skin and 14.3–16.1% in the viscera of total fatty acids. Total oil extracted by SC-CO2 had lower free fatty acid (FFA) and peroxide value (PV) content than that by Soxhlet method. The ranges of FFA and PV were 1.8–5.0 and 1.2–2.4%, respectively. It was concluded that SC-CO2 is an effective method to extract fish oil that is rich in omega-3 fatty acids from tuna by-products. Practical Applications Fish waste is a by-product of fish process and fish-based food industries. Fish oil could be extracted from tuna fish waste that contains high amount of polyunsaturated fatty acids, especially eicosapentaenoic acid and docosahexaenoic acid (DHA). Supercritical fluid extraction could be applied to obtain refined, bleached and deodorized fish oil from tuna waste without any toxic organic solvent. Tuna waste oil contains long chain of omega-3,6 fatty acids, especially DHA, which have potential health benefits in reducing the risk of various diseases.

Coating Effects of Orange and Pomegranate Peel Extracts Combined with Chitosan Nanoparticles on the Quality of Refrigerated Silver Carp Fillets

Abstract: The coating effects of orange and pomegranate peel extract combined with chitosan nanoparticles on the quality of silver carp (Hypophthalmicthys molitrix) fillets during refrigerated storage at 4C were evaluated. Solutions of orange and pomegranate peel extracts (1%, w/v) was used for dip pretreatment, and nanochitosan solution (2%, w/v) was used for the coating. The control and the coated fish samples were analyzed periodically for microbiologic (total mesophilic and psychrotrophic count), physicochemical (pH, total volatile basic nitrogen, thiobarbituric acid reactive substances) and sensory attributes. The results indicated that nanochitosan coating was effective for the preservation of silver carp fillets during refrigerated storage. However, a dip pretreatment in orange or pomegranate peel extract combined with nanochitosan coating were significantly inhibited the development of lipid oxidation in fish samples. In this context, pomegranate peel extract was significantly stronger than orange peel extract. Practical Applications The combination of orange or pomegranate peel extract and chitosan nanoparticles can be utilized as a safe preservative for fish under refrigerated storage.

Protein Degradation and Instrumental Textural Changes in Fresh Nile Tilapia (Oreochromis niloticus) during Frozen Storage

Abstract: Textural changes as well as protein degradation during frozen storage of Nile tilapia (Oreochromis niloticus) at −18C for 150 days were studied. Salt-soluble protein and protein solubility decreased significantly during the frozen storage period. Sodium dodecyl sulfate polyacrylamide gel electrophoresis was performed, and no visible changes in myosin heavy chain were observed up to 90th day of frozen storage period; however, the thickness of band was found to decrease thereafter. A new lighter band with molecular weight of 29 kDa was found on 120th and 150th day of sampling period. Actin was found more resistant to proteolysis. Texture profile analysis revealed that hardness 1, hardness 2, gumminess and chewiness gradually decreased up to 120th day, but showed an increase thereafter. Although sensory attributes decreased with the progress of frozen storage period, the fish was in acceptable condition on 150th day. Gradual toughening of muscle was recorded by the sensory panelists. Practical Application The popularity of tilapia is gaining importance for the development of different value-added fish products as well as for canning purposes. Therefore, it is important from the part of fish processor to know the changes of protein and texture profile during frozen storage. Although there was protein degradation and changes in texture profile during the study period of 150 days, the fish was in acceptable condition.

Effect of Air‐Drying Temperature on the Quality and Bioactive Characteristics of Dried Galega Kale (Brassica oleracea L. var. Acephala)

Abstract: The objective of this work was to evaluate the drying characteristics and the effect of drying temperature on the quality characteristics of Galega kale without any pretreatment. Drying times of 330, 162, 78 and 51 min provided minimal moisture contents, using temperatures of 35, 50, 70 and 85C, respectively. The L* and a* values diminished and b* increased, resulting in increasing values of chroma, total color difference and browning index, as well as decreasing values of the hue angle. A pronounced effect on the retention of total phenolic compounds and vitamin C losses ranging from 4.8 ± 9.7 to 55.5 ± 7.4% were observed. Regarding antioxidant capacity, losses from 51.7 ± 7.5 to 69.6 ± 3.7% were obtained. Chlorophyll a content decreased with increasing drying temperatures, with losses between 8.9 ± 6.7 and 35 ± 5.6%, while degradation of chlorophyll b was negligible. In conclusion, the air drying of Galega kale without any pretreatment resulted in considerable deterioration of its quality characteristics and nutritional value. Practical Applications Drying processes are often applied to preserve and increase the shelf life of vegetables. These products contain an extensive collection of phytochemicals known to provide health benefits. However, these compounds generally undergo significant degradation during drying because of their sensitivity to heat, light, oxygen, as well as to leaching phenomena. Thus, increased attention has been given to the concerns regarding the quality degradation of vegetables during drying. Galega kale was the selected vegetable as information concerning the influence of drying on the quality parameters of this vegetable is scarce. Additionally, this vegetable is known to present several healthy nutrients, but after harvest it is easily perishable. Therefore, drying could be a valuable strategy to preserve and increase the shelf life of this product. Thus, this work evaluates the impact of the drying temperature on the quality properties of Galega kale without the employment of any pretreatment.

Proximate Composition, Color and Nutritional Profile of Raw and Cooked Goose Meat with Different Methods

Abstract: Proximate composition, color and nutritional profile of raw and cooked goose breast and leg meats were investigated. Water, pH, L* value, total saturated fatty acid (SFA), total polyunsaturated fatty acid (PUFA), Ca, K, Mg, P and Zn contents of leg meat were higher than those of breast meat, while protein, fat, a* value, b* value, total monounsaturated fatty acid (MUFA), Na and Fe contents of breast meat were higher than those of leg meat. pH of breast meat increased with cooking, whereas pH of leg meat decreased. L* and a* values of the samples decreased with cooking, while b* values increased. Cooking caused a decrease in total MUFA content of breast meat, whereas total PUFA content increased. On the other hand, total SFA content of leg meat decreased with cooking, while total MUFA content increased. Cooking caused an increase Ca, Mg, P, Fe and Zn contents of breast meat, while only Fe content of cooked leg meat increased. Practical Applications There is limited information about goose meat in the literature. In addition, to the best of our knowledge, there are no reports on some quality properties of goose meat including fatty acid composition and mineral content and the effect of different cooking methods on them. Therefore, in the present study, we aim to explore some chemical composition (water, crude protein and crude fat), physicochemical properties (pH and color), fatty acid composition and mineral contents of raw and cooked goose meat with different cooking methods.