Effect of Pulsed Electric Fields on the Shelf Stability and Sensory Acceptability of Osmotically Dehydrated Spinach: A Mathematical Modeling Approach.

This study focused on the osmotic dehydration (OD) of ready-to-eat spinach leaves combined with the pulsed electric field (PEF) pre-treatment. Untreated and PEF-treated (0.6 kV/cm, 0-200 pulses) spinach leaves were osmotically dehydrated at room temperature for up to 120 min. The application of PEF (0.6 kV/20 pulses) prior to OD (60% glycerol, 25 °C, 60 min) lowered water activity (aw = 0.891) while achieving satisfactory product acceptability (total sensory hedonic scoring of 8). During the storage of the product (at 4, 8, 12, and 20 °C for up to 30 d), a significant reduction in total microbial count evolution was observed (9.7 logCFU/g for the untreated samples vs. 5.1 logCFU/g for the PEF-OD-treated samples after 13 d of storage at 4 °C). The selection of these PEF and OD treatment conditions enabled the extension of the product shelf life by up to 33 d under chilled storage. Osmotically treated spinach could find application in ready-to-eat salad products with an extended shelf life, which is currently not possible due to the high perishability of the specific plant tissue.

Influence of modified governing liquid on shelf-life parameters of high-moisture mozzarella cheese.

The roles of mesophilic lactobacilli in cheese manufacturing and ripening have been widely studied, but their impacts, especially as additives in preserving liquids, on the high-moisture mozzarella cheese quality parameters remained underexplored. The current study studied and compared the effects of four preserving liquid formulations - brine solution (sodium chloride, as control), a salt mixture solution, and two lactobacilli solutions (Lactiplantibacillus plantarum IMC 509 in brine solution) or SYNBIO® (a 1:1 ratio of Lacticaseibacillus rhamnosus IMC 501 and Lacticaseibacillus paracasei IMC 502) - on the microbial, chemical (volatile fatty acids), physicochemical (moisture, weight, pH, colour), texture (adhesiveness, hardness, cohesiveness, gumminess, springiness, chewiness) and sensorial qualities of mozzarella stored for 30 days at 4 °C. The quality of the governing solution, including microbial content, lactobacilli viability, pH, turbidity, and smell, was also monitored. For the first 10 days of storage, all samples demonstrated similar physicochemical variations: the firmness and chewiness of the mozzarella lessened, the pH values of the liquid decreased, but cheese microbial growth increased, as did the levels of free fatty acids, the mozzarella pH values and skin whiteness. At day 20, mozzarella stored in mesophilic lactobacilli liquid, especially SYNBIO®, had a spongy structure, tasted more bitter and sour, and had lower pH values than mozzarella in the simple brine solution. Moreover, the cheese sample and liquid of SYNBIO® also presented higher coliform and Pseudomonas spp. counts than that detected in the control, the SYNBIO® liquid, especially in the later period of storage, exhibited a yogurt smell and increased turbidity. By contrast, Mozzarella packed into salt mixture liquid exhibited somewhat more adhesiveness and gumminess, a saltier taste and slightly higher microbial counts than the control sample. The mozzarella samples differed slightly in colour and texture as well. The overall quality changes suggested that the use of the studied mesophilic lactobacilli as governing liquid additives may not be appropriate for high-moisture mozzarella cheese preservation.

Characterization of spray-dried Gac aril extract and estimated shelf life of ß-carotene and lycopene.

BACKGROUND: Fresh Gac (Momordica cochinchinensis) fruit is rich in carotenoids, mainly ß-carotene and lycopene, but these compounds are sensitive to degradation. Spray drying is used to encapsulate the sensitive ß-carotene and lycopene with different materials. Only a few reports of using highly branched cyclodextrin (HBCD) have been published. Additionally, studies of ß-carotene and lycopene losses in Gac powders during storage are limited. Therefore, the encapsulation of ß-carotene and lycopene of Gac aril with HBCD by spray drying at different inlet temperatures were compared. The shelf life of ß-carotene and lycopene during storage was also calculated. METHODS: The fresh Gac aril was separated and kept frozen before the experiment. Gac aril and water (1:5 w/v) were centrifuged at 8,000 g at 20 °C for 15 min using a high-speed centrifuge (Sorval; Dupont, Wilmington, DE, USA). The supernatant was filtered twice and concentrated until 15° Brix using a rotary evaporator (R-200; Buchi, Flawil, Switzerland). The mixture of concentrated aril extract and highly branched cyclodextrin at 5% (w/v) was dried at three inlet temperatures by a spray dryer (B-290; Buchi, Flawil, Switzerland) with drying air flow rate, compressor air pressure, and feed rate set at 473 L/h, 40 m3/h, and 3 mL/min, respectively . The physicochemical qualities, particle image morphology, and estimated storage time of ß-carotene and lycopene were determined. RESULTS: Increased inlet temperatures of spray drying decreased the bulk density, ß-carotene, and lycopene content of spray-dried powders significantly. The color values of dried powders had significant differences in yellowness (b*) and chroma, but not lightness (L*), redness (a*), and hue when the inlet temperature increased from 160 °C to 180 °C. The maximum reduction of ß-carotene and lycopene observed during storage at 55 °C was 90.88% and 91.11% for 33 and 18 days. For ß-carotene, the estimated shelf-life (retention of 50% of ß-carotene) was 9.9, 48.4, and 91.6 days at 25 °C, 10 °C, and 4 °C. The shelf-life of lycopene was 26, 176, and 357 days at 25 °C, 10 °C, and 4 °C, respectively. HBCD could be potentially used as an encapsulating agent in spray-dried Gac aril, but the shelf-life of ß-carotene and lycopene needs to be improved to be useful as a food ingredient.

The Effect of Microfluidization Pressure and Tocopherol Content on the Retention of Vitamin A in Oil-In-Water Emulsions.

This work investigates the oxidative stability of vitamin A encapsulated in oil-in-water emulsions, which were prepared by using a microfluidizer. All emulsions were prepared with a fixed content of vitamin A (525 µM), corn oil (10%), water (90%), and whey protein (2%), but varying two main factors: the microfluidizer pressure (10, 50, 100, 200 MPa) and the amount of α-tocopherol (0, 0.25, 0.50, 1.00 mg/g). The content of vitamin A before and after the microfluidization process, and during the subsequent five weeks of storage at 40 °C were determined by HPLC-DAD. The results of the analysis of variance performed either on the data obtained before and after the microfluidization process or during the storage showed that the highest stability of vitamin A was obtained with the highest content of α-tocopherol and with an applied pressure between 100 and 200 MPa. The highest stability was explained by the smaller particle size of the resulting oil droplets. However, high pressures (200 MPa) showed a negative effect on vitamin A retention. These results could be useful for future formulations of retinoids.

Effects of the vat pasteurization process and refrigerated storage on the bovine milk metabolome.

This study is the first to investigate the evolution of cow milk metabolites throughout the vat pasteurization process and storage using untargeted metabolomics based on a multiplatform approach. Nuclear magnetic resonance and ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry were used for fingerprinting water-soluble nutritional compounds, and headspace gas chromatography-mass spectrometry was used to fingerprint the volatile organic compounds. This study demonstrated that vat pasteurization was an efficient and mild means of milk preservation resulting in only minor changes to the metabolites. The pasteurized milk samples exhibited a stable metabolome during the first 8 d of refrigerated storage. However, at the latter stage of storage, the concentrations of pantothenic acid and butyrylcarnitine decreased, whereas some fatty acids, organic acids, α-AA, peptides, and ketones increased. These selected metabolites that changed during milk storage could be used as potential biomarkers to track the storage conditions of pasteurized cow milk.

Effect of cold plasma on polyphenol oxidase inactivation in cloudy apple juice and on the quality parameters of the juice during storage.

Direct cold plasma treatment has been investigated as an alternative non-thermal technology as a means of maintaining and improving quality of fresh cloudy apple juice. Process variables studied included type of plasma discharge, input voltage and treatment time on polyphenol oxidase (PPO) inactivation. Spark discharge plasma at 10.5 kV for 5 min was the best treatment, with near total inactivation of PPO achieved, although good PPO inactivation was also recorded using shorter treatment times. Residual activity (RA) of PPO was 16 and 27.6% after 5 and 4 min of treatment respectively. This PPO inactivation was maintained throughout the storage trials, but decreased with samples treated for a shorter time. Plasma treatment improved key quality parameters of Golden delicious cloudy apple juice, with retention of critical quality parameters during extended storage trials. Color was the most noticeable change, which was enhanced with retention of a greener color. An increase of 69 and 64% was obtained in the total phenolic content after 4 and 5 min of treatment, respectively. Therefore, cold plasma was demonstrated to be a good alternative to traditional heat treatments for enhanced quality retention of fresh cloudy apple juice and over its storage.

Development of a new equation in fuzzy logic analysis for ascertaining appropriate dose of gamma irradiation of virgin coconut oil.

Our previous investigation had established 4.2 kGy to be the appropriate dosage of gamma irradiation for removal of obnoxious rancid-acid-odor of virgin coconut oil (VCO) on the basis of sensory and electronic nose (e nose) studies. This study endeavored to revalidate the sensory data employing fuzzy logic analysis. An equation has been developed for the first time for deriving defuzzified scores, when the sum of the first and third coordinates of the triplet (a b c) of overall sensory score was greater than 100, i.e. (a + c) > 100. This study reaffirmed 4.2 kGy to be the most preferred dose for deodorization of VCO. Besides, ranking of the VCO samples were similar by either approach. •According to the fuzzy logic method, overall sensory scores were assigned to the VCO samples under investigation, these sensory scores have been represented by a triangle and a polygon when (a+c) is less and more than100, respectively.•The coordinates of the polygon were determined and a new equation has been developed for evaluating defuzzified scores, which has been validated by similarity value analysis.•This new methodology of fuzzy logic analysis can be used to rank samples rapidly and reliably, without any complexity of conventional similarity value approach.

Effects of antioxidative substances from seaweed on quality of refined liver oil of leafscale gulper shark, Centrophorus squamosus during an accelerated stability study.

Crude liver oil of leafscale gulper shark, Centrophorus squamosus was clarified by sequential degumming, decolorization and vacuum deodorization. The refined oil was added with ethyl acetate extract of seaweeds and various physiochemical parameters were evaluated in a time-reliant accelerated storage study. Significantly greater induction time was observed for the oil supplemented with Sargassum wightii and Sargassum ilicifolium (>4.5h) than other seaweed extracts and control oil (~1h). Among different seaweeds, the ethylacetate extracts of S. wightii maintained the oxidation indices of the refined oil below the marginal limits after the study period. No significant reduction in C20-22 long chain fatty acids (1.19%) in the refined oil added with S. wightii was apparent, and was comparable with the synthetic antioxidants (1.07-1.08%). Spectroscopic fingerprint analysis of marker compounds responsible to cause rancidity signified the efficacy of S. wightii to arrest the development of undesirable oxidation products in the refined oil during storage. The antioxidant compounds, 15-(but-19-enyl)-hexahydro-13,16-dimethyl-11-oxo-1H-isochromen-8-yl benzoate (1) and 10-(but-13-en-12-yl)-5-((furan-3-yl)propyl)-dihydrofuran-9(3H)-one (2) isolated from S. wightii appeared to play a major role to deter the oxidative degradation of refined oil thereby enhancing the storage stability.

Pterodon pubescens oil nanoemulsions: physiochemical and microbiological characterization and in vivo anti-inflammatory efficacy studies

Abstract Pterodon pubescens (Benth.) Benth., Fabaceae, fruits have been investigated for their anti-inflammatory and antinociceptive activities, and have demonstrated effectiveness in inflammatory conditions. A physiochemical and microbiological stability study was conducted to investigate two nanoemulsion-based delivery systems of two different hydrophilic surfactants (polyethylene glycol-40H castor oil or polyethylene glycol-40 castor oil). The nanoemulsions, containing P. pubescens oil, lecithin, hydrophilic surfactant and water, were analyzed for droplet size distribution, polydispersity index, pH, consistency index, stability against centrifugal force, and active content/vouacapan derivatives. The physicochemical characteristics were followed for 365 days. The nanoemulsion system was evaluated for anti-inflammatory activity by using with a peritonitis model, immediately after preparation and after 365 days of storage at 25 °C. The stability study demonstrated that proper storage (25 °C) preserved the characteristics of the nanoemulsion containing 7.5% polyethylene glycol-40H castor oil, 5% lecithin, and 5% P. pubescens oil. Further, it ensured a shelf life of 365 days as a phytotherapeutic formulation. In the peritonitis assay induced by carrageenan, nanoemulsion prepared with polyethylene glycol-40H castor oil (125 mg/kg) reduced leukocyte migration, even after 365 days of storage (25 °C), highlighting its potential for the treatment of inflammatory diseases. However, further studies are needed to confirm its clinical effectiveness.

Green Tea Leaves Extract: Microencapsulation, Physicochemical and Storage Stability Study.

Green tea polyphenols have been reported to possess many biological properties. Despite the many potential benefits of green tea extracts, their sensitivity to high temperature, pH and oxygen is a major disadvantage hindering their effective utilization in the food industry. Green tea leaves from the Cameron Highlands Malaysia were extracted using supercritical fluid extraction (SFE). To improve the stability, green tea extracts were encapsulated by spray-drying using different carrier materials including maltodextrin (MD), gum arabic (GA) and chitosan (CTS) and their combinations at different ratios. Encapsulation efficiency, total phenolic content and antioxidant capacity were determined and were found to be in the range of 71.41%-88.04%, 19.32-24.90 (g GAE/100 g), and 29.52%-38.05% respectively. Further analysis of moisture content, water activity, hygroscopicity, bulk density and mean particles size distribution of the microparticles were carried out and the results ranged from; 2.31%-5.11%, 0.28-0.36, 3.22%-4.71%, 0.22-0.28 g/cm³ and 40.43-225.64 µm respectively. The ability of the microparticles to swell in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was determined as 142.00%-188.63% and 207.55%-231.77%, respectively. Release of catechin polyphenol from microparticles in SIF was higher comparable to that of SGF. Storage stability of encapsulated catechin extracts under different temperature conditions was remarkably improved compared to non-encapsulated extract powder. This study showed that total catechin, total phenolic content (TPC) and antioxidant activity did not decrease significantly (p ≥ 0.05) under 4 °C storage conditions. The half-life study results were in the range of 35-60, 34-65 and 231-288 weeks at storage temperatures of 40 °C, 25 °C and 4 °C respectively, therefore, for improved shelf-life stability we recommend that microparticles should be stored at temperatures below 25 °C.

Avaliação do perfil de acidificação e viabilidade de bactérias probióticas em misturas leite-soro para elaboração de bebidas lácteas utilizando soro de queijo Minas frescal / Profile evaluation acidification and viability of probiotic bacteria in milk-whey mixtures for beverage production using whey Minas frescal cheese

A tecnologia de fabricação de bebidas lácteas envolve a mistura de leite e soro, podendo ser fermentada por bactérias do iogurte ou probióticas e adicionada de polpa de fruta e outros aditivos permitidos. O produto final deve conter bactérias lácticas viáveis em número adequado. Os objetivos deste trabalho foram desenvolver bebidas lácteas probióticas a partir das misturas leite-soro e estudar sua vida-de-prateleira. O efeito da composição da cultura probiótica (Lactobacillus delbrueckii subsp. bulgaricus, L. acidophilus, L. rhamnosus e Bifidobacterium animalis subsp. lactis em co-cultura com Streptococcus salivarius subsp. thermophilus) e o efeito do pH final da fermentação na cinética de acidificação, pós-acidificação e contagem de bactérias probióticas foram estudados em soro de queijo Minas frescal e em diferentes misturas leite-soro. Bebidas lácteas probióticas foram desenvolvidas a partir das diferentes misturas leite-soro e a vida-de-prateleira foi determinada ao longo de 28 dias de armazenamento do produto a 4°C. As características dos produtos foram seguidas pelas determinações físico-químicas, microbiológicas e sensoriais. O soro apresentou efeito positivo sobre a velocidade máxima das co-culturas estudadas, bem como as diferentes composições das co-culturas influenciaram o parâmetro estudado. Todas as culturas apresentaram contagens maiores em pH final de fermentação 4,5, quando comparadas às obtidas em pH 5,5. A co-cultura StLb foi a mais rápida a fermentar os diferentes meios estudados e, a StLr, a mais lenta. Com a adição de açúcar e de estabilizante, os parâmetros cinéticos mostraram comportamento diferenciado daqueles obtidos em misturas leite-soro. Nas bebidas lácteas, as contagens de B. lactis mantiveram-se acima do limite exigido pela legislação até 28 dias de armazenamento do produto refrigerado. A pós-acidificação, cor e reologia variaram durante o período de armazenamento, influenciando a análise sensorial, cujos atributos obtiveram maior aceitação em bebidas elaboradas com 10% de sólidos lácteos. Os resultados indicaram que a bebida láctea elaborada com a co-cultura StBl foi a melhor alternativa para desenvolvimento de uma bebida funcional com boas características sensoriais

The technology of production of lactic beverages involves the mixture of milk fermented by yoghurt or probiotic bacteria and whey in appropriate proportions, and the addition of fruit pulp and other allowed additives. The final product should contain viable lactic bacteria in appropriate counts. The objective of this work was to develop a probiotic lactic beverage from milk-whey mixtures and to study its shelf-life. The effect of the composition of the probiotic culture (Lactobacillus delbrueckii ssp. bulgaricus, L. acidophilus, L. rhamnosus and Bifidobacterium animalis ssp. lactis in co-culture with Streptococcus salivarius subsp. thermophilus) and the effect of the pH of the end of fermentation in the acidification kinetics, post-acidification and counts of probiotic bacteria were studied in Minas frescal cheese whey and in different mixtures milk-whey. Probiotic lactic beverages were developed from different milk-whey mixtures and the shelf-life was determined along 28 days of storage of the product at 4°C. The characteristics of the products were followed by determination of post-acidification, total acidity, color, rheology, probiotic viability and sensorial analysis. Whey presented positive effect on maximum acidification rates of the studied co-cultures, as well as the different compositions of the co-cultures influenced the studied parameter. All cultures presented higher counts when fermentation was stopped at pH 4.5, when compared to pH 5.5. The co-culture StLb presented the fast acidification performance while StLr, the slowest. The addition of sucrose and stabilizer affected the acidification kinetic parameters. In probiotic lactic beverages, counts of B. lactis were higher than the limit required by the legislation until 28 days of cool storage of the product. The post-acidification, color and rheological parameters varied during shelf-life, influencing the sensorial analysis, whose attributes obtained higher acceptance in the elaborated beverage with 10% of total solids. The results indicated that the lactic beverage elaborated with the co-culture StBl was the best alternative for development of a functional lactic beverage with good sensorial characteristics