查看更多>>摘要：The aim of this work was to evaluate and study the specific proteolytic activity, antioxidant, and antiinflammatory capacity of proteolytic extracts obtained from peel and seeds of Bromelia pinguin and Bromelia karatas, as well as the effect of encapsulation on these properties. Proteolytic extracts of by-products from B. pinguin and from B. karatas with high specific proteolytic activity were encapsulated by electrospraying with agave fructans with a high degree of polymerization. The antioxidant and anti-inflammatory capacity of the capsule was analyzed in addition to its photostability. Encapsulation efficiency was assessed using scanning electron microscopy, thermogravimetry, and differential scanning calorimetry in the capsules of B. pinguin peel extracts with its high specific proteolytic activity. The antioxidant capacity and anti-inflammatory capacity decreases when the extract was encapsulated, showing stability during storage. With regard to the photostability of the capsules, the high degree polymerization agave fructans protected the compounds. The micrographs show capsules with spherical and smooth morphology, the encapsulation efficiency was 97%, and the glass transition temperature of the capsule was 160.5 degrees C. These results open a window of possibilities in which the use of these encapsulated by-products can be considered in the food industry as well as in the pharmaceutical industry.
查看更多>>摘要：Blackberry and raspberry flavonoid compounds, including anthocyanins, are known for their nutritional and health benefits. Five representative Rubus fruits (blackberry, red raspberry, yellow raspberry, black raspberry, Rubus hybrid 'Young' fruit) were examined. The yellow raspberry 'Colde Summit' had the brightest color. The Rubus hybrid 'Young' had the highest brix and 'Colde Summit' the lowest solidity-acid ratio. In total, 2118 and 1089 known metabolites were identified from five representative Rubus fruits by LC-MS in positive and negative ion modes. Isoquinoline alkaloid biosynthesis was the most enriched pathway in the biosynthesis of other secondary metabolites, followed by flavonoid and anthocyanin biosynthesis. Fewer pathways differed between red raspberry and yellow raspberry than among other Rubus fruits. Significant differences among groups occurred in cyanidin-3-sambubioside content in the anthocyanin pathway, which may be predominantly responsible for color differences. This study provides a theoretical basis for the comprehensive utilization and quality improvement of Rubus.
查看更多>>摘要：Arguably the oldest method human use to extent the shelf life of food, drying inevitably inherits undesirable physiochemical changes due mainly to how the moisture in food is removed. The present study investigated how ultrasonic pretreatment (UP) affected the color, antioxidant capacity, and rehydration kinetics of lotus seeds (LSs) subjected to subsequent microwave vacuum drying (MVD). Samples of LSs were subjected to UP at intensities of 6.08, 8.39, and 10.84 W/cm2 for 10 min, followed by MVD. UP at the highest intensity (10.84 W/ cm2) changed color by increasing L* and b* but decreasing a* and also improved antioxidant activities by enhancing hydroxyl and superoxide anion radical-scavenging activities of microwave vacuum dried LSs. These changes were correlated with the increasing of gallic acid by 17.57%, chlorogenic acid by 106.73%, caffeic acid by 47.80%, rutin by 105.07%, but decreasing the content of p-hydroxybenzoic acid by 15.47% as compared to Fresh-MVD (fresh LSs dried by MVD). Under higher ultrasonic intensity, more notches and grooves appeared on surface of dried LSs which were observed by field emission scanning electron microscopy, which increased rehydration rate. Therefore, ultrasonic technique can be employed as a pretreatment method before the drying operation in order to retain the quality of the dried products.
Oliveira Neves, Isabelle CristinaFreitas de Oliveira Meira, Ana CristinaSilveira Alexandre, Ana ClaudiaOliveira, Natalia Leite...
9页
查看更多>>摘要：Mucilage extracts from the leaves (ML) and fruits (MFR) of ora-pro-nobis were used as stabilizing agent with a mixture of carrageenans (MIX) at different concentrations for Petit Suisse cheese production. The texture, syneresis, and viscosity profiles were analyzed in fresh samples and in samples rehydrated after freeze-drying. The textural properties analyzed in the fresh samples increased as the mucilage concentrations of (ML), (MFR) and (MIX) increased. After rehydration, the values of the textural analysis decreased compared to the values of the fresh samples. Fresh and rehydrated samples exhibited pseudoplastic behavior. Greater concentration of ML, MFR and MIX increased the apparent viscosity (eta) and consistency index (K). Fresh samples showed eta at 1.76 s(-1) and K slightly higher than rehydrated formulations. Syneresis occurred among some fresh and rehydrated samples. Drying yields for freeze-dried emulsions ranged from 20.79 to 34.38 g/100 g. This study demonstrates that both ML and MFR showed promising interaction with the MIX in creating freeze-dried Petit Suisse cheese.
Feijo Correa, Jessica AudreyGarcia dos Santos, Joao VitorEvangelista, Alberto GoncalvesSchoch Marques Pinto, Anne Caroline...
9页
查看更多>>摘要：Essential oil components (EOCs) show great potential for substitution of classic synthetic preservatives in the food industry, but their intense flavor at high concentrations hinders the commercial use. When combined with phenolic acids (PAs), however, the amount of EOC needed to inhibit microbial growth can be significantly reduced. In this study, we aimed to assess the effects of several combinations of EOCs and PAs on the growth of foodborne pathogens and, thereafter, evaluate the best combination in sliced ham, a highly susceptible product to bacterial contamination in retail shops. Most combinations showed additive effects in vitro against a 4-strain cocktail of Salmonella Enteritidis and a Listeria monocytogenes strain culture. The most effective combination, cinnamaldehyde (CINN) and 2-hydroxycinnamic acid (HCA), was evaluated in ready-to-eat (RTE) cooked ham. A package system based in filter papers was designed for continuous delivery of cinnamaldehyde (CINN) and 2hydroxycinnamic acid (HCA) into the meat matrix. The treatment showed no significative effects in pathogen populations, instrumental color or pH throughout shelf life. Storage time exerted statistical influence in pH, but values remained as expected for ham. L. monocytogenes population varied through storage time, probably due to the psychrotrophic nature of this species.
Su, TongchaoLi, GuangleiJiang, JikaiGao, Haiyan...
14页
查看更多>>摘要：The freezing properties and retrogradation of potato starch gels were studied. The freezing points of the starch gels decreased with increasing starch concentration and ranged from -0.7 degrees C to -1.4 degrees C. The water in the gel was partially frozen at -3 degrees C and was essentially frozen at -6 degrees C. The glass transition temperatures of potato starch gels increased with the increase of starch concentration and ranged from -3.69 degrees C to -3.23 degrees C. Therefore, -3 degrees C was selected as the subfreezing temperature for potato starch gel, and the retrogradation characteristics of gel with 8% potato starch concentration (w/w) were investigated at this temperature. The results showed that the hardness of starch gel stored at -3 degrees C was stronger than that at other temperatures, and the relaxation times T23 and T24 were shorter. Potato starch gel stored -3 degrees C had better rheological properties and higher relative crystallinity than those of the other gels, and still exhibited B-type crystallinity according to X-ray diffraction analysis. Thus, potato starch gel has a higher retrogradation rate and better gel-related properties at subfreezing temperatures than those at other temperatures, which represents a new approach for the aging of potato starch products.
查看更多>>摘要：Although the grape surface appears to be normal under high temperature during the selling period, the nutritional quality of grape might be greatly affected. Phenolics content and composition are key indicators reflective of grape's nutritional quality. Herein, the paper investigated effects of short-term high temperature (40 degrees C; 2 h) on grape phenolics from five table grape varieties to evaluate grape quality. Twenty-three phenolics were identified and quantified through UHPLC-ESI-qTOE-MS2 and UHPLC-QQQ-MS2, respectively. The results observed that short-term high temperature significantly reduced flavonoids in European and American varieties. In Eurasian varieties, high temperature induced the accumulation of stilbenes and flavonols compounds while lowered other compounds. Myricetin 4'-methylether-3-O-rhamnoside, a differential metabolite responding to high temperature in all table grapes was screened. Combining with the analysis of molecular level, high temperature down-regulated the phenolics biosynthesis-related genes involved in phenolics metabolic pathways (flavonols, stilbenes, anthocyanins and flavan-3-ols metabolic pathways) in grapes except Muscat de Hambourg grapes, such as the expression of VvUFGT, VvANR, VvLAR, VvFLS, VvSTS, VvF3'5'H and VvAOMT. Our findings suggest that short-term high temperature during the selling period is not conducive to consumer expectations, due to the partial loss of grape nutrition quality.
查看更多>>摘要：The objective of this study was to investigate the nitrite-degrading capacity of polyphenols in sea buckthorn and explore the relationship between structures and degradation capacity with quantum chemistry. The results showed that polyphenols in sea buckthorn had a higher nitrite degrading capacity than other compounds, with the nitrite-degrading rate of 75.9%, the chlorogenic acid, isorhamnetin, luteolin 3'-O-arabinoside, L-epicatechin, isosinensetin, rutin, luteolin 3'-O-beta D glucuronide, catechin, quercetin 3'-O-glucoside, epigallocatechin contents changed significantly in the presence of nitrite. The bonding dissociation energy indicated the Delta E of chlorogenic acid for the 7-OH site was 290.2853 kcal/mol, lower than other phenolic monomers, while Mulliken electron density difference of oxygen and hydrogen in corresponding hydroxyl group was larger than other polyphenols, which were in accordance with the higher nitrite degradation. These results indicated that the nitrite degradation rates were closely related to bonding dissociation energy and Mulliken electron density, and could be estimated by the two indicators.
Silva, Patricia Maria Onofre ColomboSanches, Marcio Augusto RibeiroBarretto, Tiago LuisDarros-Barbosa, Roger...
9页
查看更多>>摘要：The effects of the application of ultrasound and the content of NaCl in the brine on the technological and diffusion properties in the wet salting of beef were evaluated. Beef samples were immersed in brines containing different content of NaCl (100, 200 and 300 g of NaCl/L of water) and subjected to two different treatments: static brine (SB) and brine with ultrasound (US). Wet salting with ultrasound increased (P < 0.05) the NaCl content, reduced (P < 0.05) the denaturation temperature of myofibrillar proteins, reduced (P 0.05) the water activity and did not affect (P 0.05) the intensity of lightness (L*), redness (a*) and yellowness (b*). None of the effects (P 0.05) were significant for pH. Based on the results under the given operational conditions (600 W; 20 kHz), ultrasound is a technology with potential for accelerating the process of wet salting of beef, reducing the salting time and also providing technological advantages related to the properties of proteins.
Angonese, MarianaMotta, Gabriel Emilianode Farias, Natalia SilvaMolognoni, Luciano...
9页
查看更多>>摘要：This study aimed to characterize and compare pulps of two species of organic dragon fruits, Hylocereus undatus and Hylocereus polyrhizus, grown at the same edaphoclimatic conditions in terms of bioactive compounds and physicochemical aspects. No significant differences were observed between purple and white pulps concerning moisture, ascorbic acid concentration, and DPPH-assay antioxidant activity. Purple pulp demonstrated higher values for pH, Folin-Ciocalteau reducing capacity, and FRAP-assay antioxidant activity, lower acidity, and expressive total betalain content, suggesting higher bioactive potential. The main phenolic compounds identified in purple pulp were rutin, hesperidin, ferulic, and sinapic acids, while the white one was rich in chlorogenic acid. The major organic acids identified in both pulps were malic, citric, formic, pipecolic, and ascorbic. Pipecolic acid was detected in both, although more predominant in purple pulp, in remarkable concentrations, being the first report of it in the Cactaceae family. The found results indicate potential bioactivity, contributing to confirm the status of superfruit of these exotic fruits.
NSTL
Elsevier