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关键词： frozen storage   mozzarella cheese   proteolysis   oxidation  

摘要： High-moisture mozzarella is one of the most-exported Italian cheeses worldwide, but its quality is affected by storage. Freezing is regarded as a solution to decrease product waste, extend market reach, and increase con-venience, but its effect on quality has to be estimated. In this study, the details related to proteolysis, physico-chemical properties, and sensory quality parameters of high-moisture mozzarella as a function of frozen storage (1, 3, and 4 mo) and subsequent refrigerated storage after thawing (1, 3, and 8 d) were evaluated. Frozen cheeses stored at -18 degrees C showed a higher extent of pro-teolysis, as well as different colorimetric and sensory properties, compared with the fresh, nonfrozen control. Sensory evaluation showed the emergence of oxidized and bitter taste after 1 mo of frozen storage, which supports the proteolysis data. The extent of proteolysis of frozen-stored cheese after thawing was greater than that measured in fresh cheese during refrigerated stor-age. These results help better understand the changes occurring during frozen storage of high-moisture moz-zarella cheese and evaluate possible means to decrease the effect of freezing on the cheese matrix.

关键词： TP microcapsules   LZM   PVA coating   Sustained-release   Antibacterial mechanism  

摘要： Tea polyphenol (TP) has excellent preservation effect on the aquatic product, however, its long-term antibacterial and preservation property is poor due to its volatilization. Therefore, a novel sustained -release formulation of TP should be developed for improving the applicability. In this study, the TP microcapsules/LZM-PVA composite coatings with gradual slow release properties were prepared by tape-casting method. Its micro-morphology was characterized and its physicochemical properties were determined. Meanwhile, the antibacterial properties and mechanism of the composite coatings were studied with Pseudomonas fluorescens and Shewanella putrefaciens, the dominant spoilage bacteria in aquatic products, as the objects. The results show that the addition of TP and other substances affects the structure of PVA coatings, and changes the intermolecular force of PVA, the coatings is wrinkled and denser, which effectively improve the mechanical properties of the PVA coatings, and finally lead to the decrease of air permeability. Among them, the TP microcapsules/LZM-PVA composite coating has the best mechanical properties, the least amount of CO2 and water vapor penetration. The results of antibacterial experiments show that the PVA coating without preservatives has no antibacterial property. Compared with the bacterial cells treated by the corresponding composite coatings without LZM, the integrity of the cell membrane is poor and the permeability is higher after treated by the composite coating with LZM, which is due to the synergistic antibacterial effect of TP and LZM. More importantly, when TP is replaced by TP microcapsules, the antibacterial ability of the composite coatings is poor at the initial stage. However, TP is embedded in the space network structure formed by CS-sodium tripolyphosphate. TP in the coatings can be released slowly from microcapsules to coatings, and then from coatings to the culture medium, which prolong the antibacterial effect time and c

关键词： Suspensions (fluids)  

摘要： Tropical fruits have organoleptic and nutritional characteristics that are desired by consumers. The cape gooseberry (CG), strawberry (S), and blackberry concentrate (BC) contain a large number of bioactive compounds. The aim of this research was to determine the influence that a composition of a suspension based on CG, S, and gum arabic (GA) had the stability of a colloidal system. The emulsion was homogenized. A central composite experimental design was used and the independent variables were: % of cape gooseberry solids (STC) (50%-62%), strawberry solids (STS) (18%-24%), and gum arabic solids (STGA) (0.4%-0.6%). The dependent variables were viscosity (mu), zeta potential (zeta), particle size (D-10, D-50, D-90), total solids (STCS), spectral stability index (R), and antioxidant activity (ABTS and DPPH). The suspension was experimentally optimized with the following results: STC:50%, STS:18.9%, STGA:0.6%, mu:485.27 +/- 8.46, |zeta|:20.03 +/- 1.04, D-10:14.41 +/- 1.61, D-50:165.20 +/- 3.36, D-90:428.52 +/- 17.53, STCS:11.20 +/- 0.18, R:0.22 +/- 0.03, ABTS:1,307.41 +/- 18.71, and DPPH:1632.56 +/- 73.19. Experimental validation of the optimal suspension formulation conditions showed good results, which meant that a stable suspension was obtained with high antioxidant activity. Practical applications The following research establishes the optimal formulation of a suspension based on strawberry, blackberry, and cape gooseberry. This was carried out in order to guarantee a quality feed (high in antioxidants and physicochemical stable) for the spray-drying process. It is well-known that obtaining a good product in a powder form depends largely on the good quality of the feed suspension. The cape gooseberry, strawberry, and blackberry are fruits with a great variety of bioactive compounds, although they have a short shelf life when they are in a fresh stage. Thus, it is considered important to develop products that largely preserve the nutritional properties of these frui

关键词： Turkish coffee   Roasting   Milling   Brewing   Storage  

摘要： Turkish coffee is a special coffee due to its roasting, milling, brewing and storage processes. The roasting, milling, brewing and storage processes mainly affect the quality and physicochemical properties of Turkish coffee. The aim of this study is to determine;i) the optimum roasting method;oven (160, 180, 200 and 220 degrees C), microwave (350, 490, 700 W) or infrared (600, 1200 W), ii) the effects of different milling methods (cutter and hammer), iii) the effects of initial brewing temperature and water hardness, iv) the ideal brewing method (copper and electrical) and v) the ideal storage conditions. Microwave roasting at 350 W for 30 min and grinding with a cutter mill were found to be the better processes when compared to the others. Furthermore, the highest foam volume was obtained by using tap water at 4 degrees C and by brewing with a copper pot. The cold storing of Turkish coffee powder is a good storage condition to preserve the freshness;therefore, higher foam volume and stability were achieved under these conditions.

关键词： diabetes mellitus (DM)   erythrocytes   low-intensity light therapy (LILT)  

摘要： The physicochemical characteristics of erythrocyte membranes from the peripheral whole blood of rats and the erythrocytes washed with physiological solution, using the method of acid hemolysis, under diabetes mellitus conditions and against the therapy based on low-intensity blue light emission in the visible light range have been studied. The use of low-intensity light therapy (LILT) led to a decrease in the resistance of erythrocyte membranes to the action of acid hemolytic in the control group animals. Under diabetes conditions, LILT prolonged total hemolysis and reduced the count of hemolysed erythrocytes relative to the indices in the group of animals with DM. No expressed hypoglycemic effect due to the LILT was observed in sick animals, and the content of glycolysed hemoglobin tended to decrease.

关键词： Rice starch   Drought and heat stress   Morphological structure   Physicochemical properties  

摘要： High temperature (HT) and drought stress (WS) severely affect rice quality by altering the starch structure in rice. The morphological and physicochemical properties of starches isolated from two rice varieties grown under three stress treatment (HT, WS and WS + HT) during the grain filling stage were investigated. The results showed that WS increased amylose content (AC%) and the proportion of large starch granules (LSG) and made the surface of the starch granule smooth and flat. As a result, a lower relative crystallinity, surface order, swelling power, setback viscosity and gelatinization enthalpy were caused. HT decreased AC% and milled rice rate, but increased chalky rice rate, the number of LSG and the large air space and pits on the surface of the starch granules. As a result, a higher relative crystallinity, surface order, swelling power, setback viscosity and gelatinization enthalpy were caused. Similar results were observed under the treatment of WS + HT, indicating that there is a mild antagonistic effect on rice starch when the HT and WS occur simultaneously.

关键词： Common vetch   Starch   Physicochemical property   Functional property  

摘要： It is believed that common vetch (Vicia sativa L.) contains a relatively high quantity of starch. In this study, the starch content of 36 common vetch accessions was monitored, within the range of 20.56-47.53% on a whole seed basis. The amylose content ranged from 17.75 to 38.68% on a dry starch basis. Among them, 8 common vetch accessions were selected for physicochemical and functional analysis, by comparing with 2 smooth pea cultivars and 2 chickpea cultivars. The isolated starches differed significantly in granule morphology, thermal parameters and pasting properties. The shapes of common vetch starch granules were kidney, spherical or oval varied with size from 7.77 to 23.16 mu m. The crystalline structures of all starches were C-type. The relative crystallinity of common vetch starches ranged from 22.70 to 34.32% and gelatinization temperature ranged from 63.10 to 66.80 degrees C. A wider variation of breakdown (BD) (197-910 cp) was observed in common vetch starches than smooth pea and chickpea starches. And the setback (SB) (1314-2221 cP) was lower than that of the pea cultivar P2 and two chickpea cultivars. These could lead common vetch starches to a broad application prospect.

关键词： Quinoa   Soluble dietary fiber   Physicochemical property   Functional property  

摘要： As it is well documented that the phytochemical composition and bioactive profile of quinoa are influenced by different phenotypes, we analyzed the physicochemical and functional characteristics of different quinoa soluble dietary fiber (SDF). SDF was prepared through ultrasound-assisted enzymatic extraction from three colored quinoa brans. After purification, the yield of SDF from white (W-SDF), red (R-SDF) and black quinoa bran (B-SDF) was 2.2%, 5.7% and 5.9%, respectively. Compared with R-SDF and B-SDF, W-SDF had a higher molecular weight (1.72 x 10(6) Da) and lower zeta-potential (- 32.16 mV), although their monosaccharide composition and Fourier transform infrared spectroscopy (FT-IR) results showed no obvious differences. The transmission electron microscope (TEM) image suggested that R-SDF exhibited a more complex and loose structure than W-SDF and B-SDF. Moreover, R-SDF exhibited higher thermal stability, gel forming capacity, bile acid binding capacity, water-holding capacity and glucose adsorption capacity than those of B-SDF and W-SDF. Taken together, SDF extracted from quinoa especially from red quinoa might be a promising candidate for the development of novel functional food ingredients.

关键词： Rare honey   Palynological analysis   Physicochemical analysis   Biochemical analysis   Volatile compounds   Chemometrics  

摘要： Obtained directly from beekeepers in Portugal and Greece, some rare honey samples were subjected to melissopalynological, physicochemical (degrees Brix, moisture, pH, electrical conductivity, free acidity, total dissolved solids, salinity, liquid resistivity, specific weight, CIELAB colour parameters, Pfund, and colour intensity), biochemical (diastase activity, vitamin C, antioxidant activity, and total phenolic content), and volatile compounds analyses. Results showed that honey samples from Portugal were dominated by pollen grains of Anarrhinum bellidifolium (L.), whereas those from Greece were honeydew of not specific type, possessing a diverse pollen spectrum and few honeydew elements. The implementation of one-way analysis of variance showed significant differences (p < 0.05) among the two honey types in the majority of physicochemical, biochemical, and to a lesser extent in the volatile compounds. These were 34 in total, belonging to alcohols, aldehydes, benzene derivatives, esters, hydrocarbons, ketones, sulfur compounds, and terpenoids. Application of correlation, regression, and stepwise linear discriminant analyses indicated some potential fitting among the investigated parameters, and classified perfectly honey samples according to botanical origin based on electrical conductivity, salinity, 2-methylbutanal, and alpha-pinene, providing a rapid tool for the classification of less common honey types.

关键词： Energy utilization  

摘要： This study aimed to evaluate the influence of drying air temperature on drying kinetics and the physicochemical properties of dried bananas. Banana slices were dried at 40, 60, and 80 degrees C. Drying was terminated when the samples had a moisture of 20%. Mathematical models were fitted to the moisture ratio. A generalized model of moisture was developed, to predict the moisture of samples as a function of drying time and temperature. The effective moisture diffusivity (D-eff), activation energy and the drying rate (DR) were calculated. Electrical energy consumption was measured. The moisture, water activity, reducing and total sugar content, acidity, hardness, and color of the dried bananas were evaluated. The moisture decreased during drying, obtaining a mean value of 20.132%. All mathematical models fitted well to the MR data, with a determination coefficient greater than 0.95. The Midilli model was that which best fitted. The higher temperature resulted in higher D-eff (3.538 x 10(-9) m(2) s(-1)) and DR, less drying time (120 min) and electrical energy consumption (4.319 kWh), higher reducing sugar content (47.51%) and hardness (28.187 N), lower acidity (1.038%), more yellow tonality (78.04 degrees), and higher chromaticity (18.49) of the dried bananas. The optimum temperature for drying bananas was 80 degrees C. Practical Applications Banana is a fruit widely consumed in the world. However, it is very perishable, causing great waste and financial loss. Convective drying is a simple and low-cost method, widely used in fruit processing to produce new products and extend the shelf life of food. The dried banana is a product of good sensory acceptance and therefore drying is a good alternative for processing the banana pulp. The temperature of the drying air is one of the principal parameters of this process since it influences the drying kinetics and the physicochemical properties of the dry product. Therefore, it is important to study different drying air temper