Araujo de Barros, Hanna ElisiaSilveira Alexandre, Ana ClaudiaCampolina, Gabriela AguiarAlvarenga, Gabriela Fontes...
7页
查看更多>>摘要：Edible seeds, especially those known by the population as nuts, have their consumption associated with func-tional appeal. The present study aimed to compare and group nine different seeds, traditional and regional, according to their similarities, in terms of moisture, total phenolic compounds (TPC) and antioxidant activity, through multivariate analyses. All results were submitted to Principal Component Analysis (PCA), Hierarchical Clusters (HCA) and Kohonen's self-organizing maps (ANN/KSOM). The seeds differed in terms of moisture content, TPC and antioxidant activity. The walnut butterfly stood out with the highest levels of TPC and anti-oxidant activity. In the multivariate analyses application, three groups were formed: i) hazel, baru, Brazil, macadamia, almond and cashew; ii) pequi and marolo; iii) walnut butterfly. It is concluded that the seeds can be separated into three groups, with ANN/KSOMs being the most self-explanatory analysis and that regional seeds are nutritionally similar to those traditionally consumed.
查看更多>>摘要：To improve the microbial stability of mildly processed acidified sauces, which are threatened by acid-tolerant spore-forming spoilage bacteria (ATSSB), this study investigated the individual effect of pH, water activity (a(w)), temperature and organic acids on the growth from ATSSB spores and their spoilage potential. The pH of nine commercial sauces was gradually increased (3.8-5.6), and 81 strains were isolated from each sauce with the lowest pH allowing microbial growth. After heat treatment and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, ten selected strains were identified to the Bacillus subtilis and Bacillus cereus species group by 16S rRNA gene sequencing. The selected isolates with three acid-tolerant reference strains all exhibited enzymatic spoilage activity (amylase, protease, lipase or lecithinase) and had D-95 degrees C -values between 0.8 and 6.4 min. None of the 13 strains grew below 10 degrees C, while the minimum growth pH varied from 4.1 to 5.4 and the minimum aw varied from 0.89 to 0.96. Moreover, the minimum inhibitory concentrations of benzoic, sorbic, acetic and lactic acids were 0.04-0.07, 0.05-0.10, 0.11-0.30 and 0.20-1.05 g/100g, respectively. This work demonstrated that the ATSSB spores were sensitive to organic acids and refrigeration, contributing to more accurate strategies to preserve the mildly pasteurized sauces with reduced acids and salts.
Salas-Veizaga, Daniel MartinBhattacharya, AbhishekAdlercreutz, PatrickStalbrand, Henrik...
9页
查看更多>>摘要：Quinoa stalks glucuronoarabinoxylan (QSGAX) has been extracted by alkali and further utilized for production of two-types of xylooligosaccharides (XOs): i) enzymatically produced glucuronosylated-XOs (GXOs), and ii) a dilute acid produced mixture of non-ubstituted/substituted XOs of different degree of polymerization (DP). The respective mixtures were then separately evaluated as prebiotics by analysis of their consumption by two phylogenetically different potential probiotic bacterial strains (Bifidobacterium adolescentis ATCC15703 and Weissella cibaria strain 92), from which release of short chain fatty acids (SCFA) was also monitored. The GXOs mixture was produced using a glucuronosyl-requiring family 30 glycoside hydrolase (GH) Bacteroides ovatus (BoXyn30A), while the XOs mixture was produced by a 30 min acid treatment of QSGAX with H2SO4 [24.5 g/L] at 90 degrees C. B. adolescentis consumed both GXOs and XOs (DP 2-6), in both cases releasing acetate, lactate, pro-pionate, formate and butyrate as metabolic products. W. cibaria only consumed XOs (DP 2-4), releasing acetate, lactate and minor amounts of butyrate. This is the first study reporting the ability of GXOs consumption by B. adolescentis and shows the potential of GXOs to selectively stimulate B. adolescentis, while XOs stimulated both types of potential probiotics (B. adolescentis ATCC15703 and W. cibaria strain 92).
查看更多>>摘要：Tea is considered as a healthy beverage due to the presence of bioactive compounds. Nevertheless, the presence of caffeine adversely affects human health. Therefore, caffeine-free herbal beverages are gaining popularity as widely consumed healthy beverages; however, only few studies have thoroughly investigated the characteristics of herbal infusions. Therefore, the study was focused to develop Kyoho grape skin herbal infusions to study their proximate, functional as well as sensory attributes. Moreover, similarities in formulations were assessed by principal component analysis (PCA) and hierarchical cluster analysis (HCA). The results showed that the Kyoho grape skin formulations (40%, 50%, 60%, and 70%) had insignificant amounts of proximate composition. The amount of total phenolics (0.08-0.14 mg GAE/mL) and flavonoids (0.08-0.10 mg QE/mL) was associated with their antioxidant activities (DPPH center dot of 19.98%-65.20%). Formulations with 40% and 50% Kyoho grape skin received acceptable sensory scores (>6) that showed a high homogeneity between two formulations using PCA (PCs 1: 50.74% and 2: 14.26%) and HCA sub-clusters. Thus, formulations prepared with 40% and 50% of Kyoho grape skin could be considered as a suitable herbal beverage to be produced on an industrial scale.
查看更多>>摘要：This research aimed to study the effect of dimethyl dicarbonate (DMDC, 0-250 ppm) on inhibition kinetic of pathogenic and spoilage microorganisms (Escherichia coli, Saccharomyces cerevisiae and Lactobacillus plantarum) and the effect of DMDC and pasteurization on physiochemical properties (total soluble solid, pH, titratable acidity, ascorbic acid, total phenolic content, anthocyanin content and antioxidant activity), microbial counts and sensory attributes of pomegranate juice during cold storage (4 degrees C). The results showed that inhibition kinetic of all microorganism tested in this study followed the first-order kinetic. Before storage, no significant differences (p > 0.05) were found in total soluble solid, pH, titratable acidity and antioxidant activity among the treatments. During storage, pH, ascorbic acid, total soluble solid, total phenolic content, anthocyanin content and antioxidant activity of all samples tended to decrease and titratable acidity, total plate count and yeast and mold count showed an increasing trend during cold storage at 4 degrees C. The shelf life of pomegranate juice was extended by DMDC approximately 8 days compared to control. In addition, DMDC did not significantly affect sensory properties of pomegranate juice (p > 0.05). This research could be used as a guideline for the development of DMDC as a non-heat processing to preserve quality with extended shelf life of juices for health-conscious consumer.
查看更多>>摘要：The study is about the watermelon seeds protein extraction using the specific energy per pulse (EPP) (W/g) as the operation parameter for optimization by liquid-phase pulsed discharge (LPD) at various scales, in comparison with the extraction using discharge voltage (kV) as the operation parameter for optimization by LPD. The optimization based on the intrinsic parameters of EPP (W/g), liquid to solid (L/S) ratio (mL/g) and extraction time (min) were firstly implemented. The protein yield of 462.26 +/- 1.214 mg/g was obtained under optimal conditions (0.042 W/g EPP, 3.8 min extraction time and 40 mL/g L/S ratio), which was in accordance with the yield of 462.03 +/- 1.061 mg/g obtained by traditional optimization based on discharge voltage, extraction time and L/S ratio. Then, the two optimization methods were compared at larger scale of 100-280 mL solvent loading. The protein yields of the EPP optimization were 461.313 +/- 0.990, 462.102 +/- 1.034, 462.009 +/- 0.872 and 460.319 +/- 0.981, respectively, which had no significant difference. However, the protein yields of traditional optimization method decreased rapidly. Thus, the results showed that the EPP optimization method had the favorable effect on the reliability and feasibility of the scale-up LPD extraction. These indicated that the EPP accurately reflected the LPD extraction mechanism, and could replace the discharge voltage.
查看更多>>摘要：CS sufu is a fermented food composed of mixed chickpeas and soybeans. To explore the effects of the microbial community on the physicochemical and flavor properties of this product, microbial succession and metabolite changes during the fermentation stage of CS sufu production were detected using high-throughput sequencing and HS-SPME-GC-MS. The results showed that bacterial diversity was higher than that of fungi in CS sufu, and core communities included Enterococcus, Enterobacter and Rhizopus. Moreover, enriched species in different fermentation stages were significantly different. Seventeen free amino acids (FAAs) were detected at the post fermentation stage. Sweet amino acids (TSAAs) and umami amino acids (TUAAs) mainly contributed to the taste of CS sufu. A total of 106 flavor compounds were identified at the different post-fermentation stages of CS sufu production, and esters, including ethyl caproate, ethyl octanoate, and isoamyl phenylacetate, accounted for the highest proportion. Furthermore, metabolic profile and microorganism analyses showed a significant correlation between the microbial profile and dominant flavor compounds. Lactococcus and Enterococcus were positively correlated with flavor compounds. This study provided information for the analysis of CS sufu at different fermentation periods in terms of microbial diversity and metabolites, and this information is important for understanding the properties of sufu made with mixed soybeans.
查看更多>>摘要：beta-carboline heterocyclic amines (beta-CHAs) are substances widely present in food products, and are considered to have synergistic teratogenicity. In this study's experiments, the dry-heated glucose (Glc)-containing soy protein isolate (SPI) was used as a model to examine the effects of tetrahydro-curcumin (THC) on the formation of beta-CHAs. The structural characteristics of the protein, ninhydrin-reactive amino nitrogen (NRAN), changes in antioxidant properties, and so on, before and after heat treatments were studied at the same time. The results showed that 1 g/100 g Glc in SPI could inhibit the formation of 1-methyl-9H-pyrido [3,4-b]indole (Harman), while promoting the formation of 9H-pyrido [3,4-b]indole (Norharman). THC could inhibit Norharman formation during the dry heat processes of Glc-containing SPI when the addition content was 1 g/100 g (P < 0.05), and the inhibitory effects increased with the increases in the content of THC. In addition, a 5 g/100 g content of THC was observed to significantly inhibit the formation of Harman. beta-CHAs and protein structures displayed good correlations, which indicated that interactions between food components may be one of the ways for exogenous additives to inhibit the formation of beta-CHAs in protein foods.
查看更多>>摘要：Bitterness in juice significantly affects consumer acceptability as well as its shelf life. Juice extracted from Kinnow fruit becomes bitter due to the presence of limonin and naringin. Therefore to remove bitterness from Kinnow juice, different debittering methods have been studied. These methods include hot water treatment, lye treatment (1-2%), Florisil (R), beta-cyclodextrin (0.5-2.5%) and their optimized treatment (NaOH 1.5% + Florisil (R) 3% + beta-cyclodextrin 2%). Significant effect of treatments on pH, acidity, and TSS (Total soluble solids) was observed. Control (P1) and treated juice samples [lye treated juice (1.5%) (P2); lye treated juice (1.5%) + Florisil (R) (3%) (P3), and juice from optimized treatment (P4)] were studied for the presence of bioactive compounds and antioxidant properties. The antioxidant profiles of control and treated juice samples were compared using different antioxidant assays. Phenolic compounds in debittered juice (P4) were significantly higher (94.5 mg GAE/100 mL) as compared to control (P1) (90.1 mg GAE/100 mL). HPLC was performed to check the presence of bitter compounds (limonin and naringin) in control and treated juice. A significant decrease in the concentration of limonin (124.45-57.89 mu g/mL) and naringin (2.38-1.26 mu g/mL) was observed in the selected combined treatment.
查看更多>>摘要：Human noroviruses (HuNoVs) outbreaks have been linked to contaminated fresh-cut produce. Propolis has been used as a folk medicine because of its extensive bioactivity and antimicrobial properties. The aim of this study was to investigate the antiviral properties of propolis water extracts (PWE) and propolis ethanol extracts (PEE) against noroviruses, and its application in fresh-cut produce. Extraction yields, total phenolic content, total flavonoid, and soluble carbohydrate content of the propolis extracts were measured to estimate their antiviral compounds. The HuNoV GII.4 and its surrogates (murine norovirus MNV-1 and bacteriophage MS2) were used to evaluate the anti-noroviral activities of propolis extracts. The polyphenol-rich extract (PEE) showed better antiviral activities than PWE. Time-of-addition experiments and TEM images suggested that PEE denatured the viral capsid protein and likely prevented adsorption and internalization of viruses into cells. The application of PEE for natural preservative in fresh juices was also analyzed. After 30 min of treatment of the four different juices, 500 mu g/mL PEE reduced MNV-1 and MS2 titers by > 3.0 log10. Therefore, the PEE containing high amounts of polyphenol improved the safety of fresh juices and could be potential candidates for the development of novel natural antiviral preservative for fresh juices.
NSTL
Elsevier