Malfatti, Luciano HeusserZampar, AlineGalvao, Alessandro CazonattoRobazza, Weber da Silva...
9页
查看更多>>摘要：Egg quality is a multidimensional concept that depends on many different parameters. Many studies have evaluated different egg quality attributes subjected to various storage conditions. The present work aimed to study the influence of three environmental parameters (temperature, storage time and relative humidity) on egg quality indicators. Through application of response surface methodology, it was verified that the temperature is the most important environmental factor affecting egg quality attributes followed by the storage time and relative humidity, respectively. Principal Component Analysis showed that most quality indexes are similar except for the eggshell percentage that represents an exterior quality indicator. An artificial neural network composed by one hidden layer and four neurons provided accurate predictions of the Yolk index and is a promising tool to evaluate egg quality.
查看更多>>摘要：Spoilage caused by microbial contamination in dried persimmon fruits processed by traditional frosting often leads to considerable economic losses. Artificial frosting has recently been considered as an alternative method to reduce the risk of spoilage, however, in this study, expansion of packaging and mildew formation were still observed. The dynamics of bacteria and fungi structure in different processes were determined. Results showed that Zygosaccharomyces and Aspergillus were the predominant genera in spoiled fruits in the packaging phase. During the artificial frosting, Wickerhamomyces (15.91%) and Candida (6.82%) were the predominant gasgenerated yeasts and Aspergillus (20.45%) and Penicillium (15.91%) were consistently the dominant genera causing mildew. To reduce the contamination problem, pulsed light (24 J/cm2) were adopted on Day 0 of frosting and no fungi were detected on Day 3 post-frosting, which indicated to decrease significantly the amounts of Wickerhamomyces, Candida, Aspergillus, and Penicillium. Additionally, the results of the high-throughput sequencing suggested that the proportions of these predominant microorganisms were also decreased significantly during frosting. These results showed that pulsed light treatment in the artificial technique could almost overcome the problems of packaging expansion and mildew formation.
Neves, Tais Teixeira dasBrandao, Rafaela MagalhaesBarbosa, Richard BispoCardoso, Maria das Gracas...
11页
查看更多>>摘要：Temperature and water activity (aw) are both responsible for the growth and production of ochratoxin A (OTA) by Aspergillus species in coffee. To prove this, we tested the effect of environmental factors combined with green coffee composition on the risk of OTA production as well as the efficiency of using Saccharomyces cerevisiae to control the growth of Aspergillus ochraceus, A. westerdijkiae, and A. carbonarius, OTA production and biosynthetic genes expression regulation levels. The results showed a higher growth rate and OTA risk index (ORI) for the three fungal isolates at 21 degrees C and 0.98 aw. Temperature affected the growth of the isolates negatively. The ORI was influenced synergistically by aw and antagonistically by temperature. The best condition for biological control by using S. cerevisiae CCMA 0159 was observed at 28 degrees C and 0.99 aw. Temperature and aw directly affected OTA production and biological control efficiency, but at different values. A. carbonarius CCDCA 10507 showed better growth and a greater risk of contamination in coffee. S. cerevisiae CCMA 0159 significantly reduced the risk of contamination by Aspergillus using substrate competition as strategies, acting on down regulation of OTA's biosynthetic gene expression, including hal and p450.
查看更多>>摘要：To understand the impacts of high hydrostatic pressure (HHP) processing on the microstructure and properties of pectin, an aqueous solution of apple pectin (50 g/L) was treated at 200, 400, and 600 MPa for 30 min. The chemical structure and properties of resultant pectin were characterized and compared with those of native pectin (0.1 MPa). The contents of alpha-1,4-linked D-galacturonic acid and reducing sugar in pectin did not change after HHP, whereas the degree of esterification of pectin increased slightly. Fourier transform infrared spectroscopy showed that no chemical conversion of pectin occurred during HHP process. For the first time, molecular dynamics simulation revealed that the hydrophobic hydration of the methyl group dramatically improved under HHP, thereby enhancing pectin dissolution in water. In turn, this result increased the aqueous pectin solution's apparent viscosity and stability, which are very important for fruit- and vegetable-based products containing pectin.
D'Incecco, PaoloLimbo, SaraHogenboom, Johannes A.Pellegrino, Luisa...
10页
查看更多>>摘要：Drinking milk with longer shelf-life is nowadays required to have access to markets of distant countries. Novel technologies for milk processing, alternative to conventional heat-treatments, may provide milk industry with reliable, efficient and clean equipment for drinking milk manufacture. This review addresses the most promising of these technologies, either under experimental examination or already commercially available. In particular, scientific literature documenting the performances of ohmic heating, microwaves, radio frequency, microfiltration, high pressure, pulsed electric field, and ultrasounds is presented. Attention is given to the respective effectiveness in destroying microorganisms, inactivating enzymes, and avoiding damage to milk components, as well as to the consequent microbiological and physicochemical stability of the processed milk during storage. Although most technologies allow to destroy or remove vegetative bacterial cells, so far none proves to represent a comprehensive alternative to conventional heat treatments. The combination of an alternative technology with mild thermal treatments represents, at the moment, the sole realistic approach to produce fresh-like/high quality pasteurized milk.
查看更多>>摘要：Salmonella has been a recurring issue in the papaya industry. The purpose of this study was to determine the effect of post-harvest storage conditions on the growth kinetics of Salmonella in fresh-cut papaya. Papaya samples were spot inoculated with nalidixic acid adopted Salmonella spp (4-strain) at 4-5 log CFU/g and then stored in an environmental chamber at six different temperature (4, 12 and 21 degrees C) and relative humidity (55 and 90%) combinations for up to 14 days. The levels of Salmonella and the changes in pH, TSS, color, and water activity of papaya were determined. Increasing the storage temperature from 4 to 21 degrees C and RH from 55 to 90% increased the log survival. However, no significant effect (P > 0.05) of RH was observed when the samples were stored either at 12 or 4 degrees C for 14 days. Both Baryani-Roberts (R20.794-0.975) and Biphasic models (0.793-0.975) best fitted the experimental data at the tested storage conditions. Salmonella showed a maximum growth rate ranging from -0.0207 to 0.0632 (1/h) and the highest growth rate was observed at 21 degrees C and 90% RH. These findings demonstrate that better control over storage temperature and RH is critical to mitigate the risk of Salmonella in papaya.
Barbosa, Cosme DamiaoUetanabaro, Ana Paula TrovattiSantos, Wildon Cesar RodriguesCaetano, Renata Gomes...
9页
查看更多>>摘要：Kombucha is a drink produced by spontaneous fermentation, and several studies have been conducted to unveil its microbiological and physicochemical aspects with numerous human health claims. The integration of these results is fundamental to understand and discuss the biological activities attributed to kombucha. In the present study, we isolated bacteria and yeasts involved in the fermentation of kombucha produced with green (GK) and black (BK) teas, as well as the amplicon metagenomic of the microbial communities (16S and ITS) during 0, 3, 5, 10, and 15 days of fermentation, at 28 degrees C. Microbial communities were linked to key biochemical parameters monitored during fermentation such as pH, total titratable acidity, total reducing sugars, polyphenols, acetic acid, and ethanol production. Moreover, ordination analysis (principal component analysis, PCA) revealed clear GK and BK separation groups during the fermentation process. Caffein, gallic acid, and chlorogenic acids majorly influenced the separation of GK and BK. Furthermore, the presence of Komagataeibacter spp. and catechins exerted selective pressure against microbial contamination. This study essentially contributes to the knowledge about the effects of integrated microbiota to the chemical results of the kombucha fermented in GK and BK teas.
Longvah, T.Boiroju, Naveen KumarPrasad, V. S. S.Kumar, Kiran O....
8页
查看更多>>摘要：Comprehensive nutrient profiling of 251 modern rice germplasm was carried out as brown rice and milled counterparts by grain types to assess their nutrient supply potentials. Significant variability was observed in most nutrients, which was very large for micronutrients. Except for moisture and energy, all other nutrients evaluated were significantly affected by the degree of milling and grain types. Using nutrient density score (NDS), several germplasm with a much better nutrient profile than the rest were identified. Rice as a staple food is the most crucial nutrient contributor to the recommended dietary allowances in the rice-based Indian diet for most nutrients, but it was low for fat, iron, riboflavin, and calcium. By far, brown rice has the best potential for nutrient supply. The study highlights the importance of intra-varietal nutrient differences within the rice to help select and breed superior germplasm to improve nutrient intakes considerably among populations.
查看更多>>摘要：The effect of Mesona chinensis polysaccharides (MCP) on the gel, rheological, and structural properties of debranched waxy maize starch (DWMS) were investigated. The gel strength of DWMS-MCP gels first increased and then decreased with MCP concentrations. Addition of MCP (<= 1 g/100 g) revealed higher dynamic modulus with a more solid-like behavior. However, an excess of MCP had the opposite effect. Inverted fluorescence microscopy showed that the network-like structure of DWMS became firmer and denser with addition of 0.5 and 1 g/100 g MCP, whereas it became weaker and more scattered at higher MCP concentrations. Fourier transform infrared spectroscopy and X-ray diffraction analysis showed that the appropriate amount of MCP (0.5 and 1 g/ 100 g of DWMS) could significantly increase the values of 1047 cm-1/1022 cm-1 and relative crystallinity, suggesting that the DWMS recrystallization was accelerated by MCP. Low-field nuclear magnetic resonance showed that a stronger gel network led to more strongly bound water. The effect of MCP on performance of DWMS gel mainly through the interaction with DWMS or the phase separation with DWMS at high MCP concentrations. Based on these measured results, a potential mechanism for the impacts of MCP on DWMS gel was proposed.
Liu, YunjiaoSeah, Rui HongRahaman, Mohammed Salahudeen AbdulLu, Yuyun...
9页
查看更多>>摘要：This work investigated the impact of co-fermentations of Oenococcus oeni and Lachancea thermotolerans on chemical constituents of spent coffee grounds (SCG) hydrolysates with added yeast extract. O. oeni Lalvin 31 and L. thermotolerans grew well in co-cultures, but the yeast died early in two co-cultures with O. oeni Enoferm Beta and O. oeni PN4. Compared with the monoculture of yeast only, co-inoculation with O. oeni did not significantly affect sugar consumption but reduced ethanol production. In addition, co-fermentation significantly altered organic acids profiles. Furthermore, the fermented SCG hydrolysates from co-culture of L. thermotolerans and O. oeni Lalvin 31 retained more alkaloids (e.g. theophylline and trigonelline) and had higher amounts of ethyl acetate, methyl acetate and acetoin as compared with those of control. Hence, simultaneous malolactic fermentation by selected O. oeni and alcoholic fermentation by L. thermotolerans may provide a new strategy to valorize SCG for developing novel alcoholic beverages.
NSTL
Elsevier