查看更多>>摘要：Essential oils have attracted increasing attentions due to their broad-spectrum antimicrobial activities and generally recognized as safe (GRAS) regulatory status. However, their low-solubility in water and reduced effectiveness in food matrices limit the commercial application in food industry. In this study, we used ultrasonic emulsification, medium-chain triacylglycerol (MCT) and phosphate-buffered saline (PBS) to formulate a highly stable and water-dispersible litsea cubeba essential oil (LCEO) nanoemulsions. After emulsification, a minimizing droplet size of LCEO nanoemulsions was achieved at approximately 100 nm in diameter, resulting in an increase in the water solubility and better stability at 4 degrees C and 25 degrees C. Furthermore, the bioactivities (antibacterial, antioxidant and antibiofilm properties) of LCEO nanoemulsions were greatly improved after emulsification, suggesting that nano-emulsification is beneficial for the value development of various essential oils and the LCEO nanoemulsions could be used as a novel food preservative for controlling bacterial growth and preventing oxidative deterioration in foods.
查看更多>>摘要：Bacillus species have been found in Sichuan paocai (SCP); however, their role in SCP remains to be elucidated. In this study, the effect of Bacillus subtilis Y61 inoculation on physicochemical properties, bacterial community and metabolic profile of SCP fermented for seven days was investigated. The results revealed that inoculation with B. subtilis Y61 could accelerate the decrease in pH and reduce the salinity of SCP, promote the growth of lactic acid bacteria (LAB), such as Lactobacillus and Lactococcus, and inhibit the growth of some opportunistic pathogens. Additionally, forty differential metabolites were observed in the ripe SCP, among which the contents of linalool, gamma-terpinene, lactic acid, oxalic acid and most amino acids, were significantly higher in B. subtilis Y61-inoculated SCP fermentation compared to those in the spontaneously fermented SCP. These findings suggest that the inoculated fermentation of B. subtilis Y61 can enhance the quality and safety of SCP as well as can shorten fermentation time.
查看更多>>摘要：In order to improve the drying efficiency while maintaining product quality, pulse-spouted microwave freeze-drying (PS-MFD) was applied to the dehydration process of blueberries. The present study was carried out to establish a strategy for intelligently determine sublimation/desorption drying transition point (TPS-A) and drying endpoint of blueberry during PS-MFD process. Back-propagation artificial neural network (BP-ANN) model was used to establish the relationship between low field nuclear magnetic resonance (LF-NMR) spectrum and moisture content (MC) as well as between near infrared (NIR) spectrum and MC. Then the two models were applied to predict the moisture content of blueberry during PS-MFD process. Model fitting results showed that BP-ANN models based on LF-NMR spectrum and NIR spectrum could accurately predict the moisture content of blueberries. BP-ANN model of LF-NMR-MC couldn't capture the signal of free water during the early stage of PSMFD (about 90 min), while BP-ANN model of NIR-MC had moisture content output values of blueberries during the whole PS-MFD process. The TPS-A and drying endpoint of blueberry during PS-MFD process could be accurately determined by comparative analysis of PS-MFD blueberry samples moisture content output values obtained from two models.
查看更多>>摘要：The present study investigated the in situ production of vitamin B12 in eleven cereal, pseudo-cereal and legume materials by fermentation with Propionibacterium freudenreichii DSM 20271 and Levilactobacillus brevis (formerly Lactobacillus brevis) ATCC 14869. P. freudenreichii was used as the vitamin producer and L. brevis was selected to improve the consistency and microbial safety of the process. The study showed that more than 300 ng/g dw of vitamin B12 (daily requirement: 2.4 ug) were produced during fermentation in most of the studied brans and legumes. The highest vitamin B12 production was observed in the fermentation of the rice bran (ca. 742 ng/g dw), followed by the fermentation of buckwheat bran (ca. 631 ng/g dw). Furthermore, partial least squares (PLS) regression analysis suggested that the production of vitamin B12 was greatly influenced by the nutrient composition of the fermented raw materials. Meanwhile, L. brevis was found to effectively inhibit the growth of Enterobacteriaceae during fermentation. These results demonstrated that fermentation of cereal, pseudo-cereal and legume materials with P. freudenreichii and L. brevis is effective in fortifying plant-based food with vitamin B12.
查看更多>>摘要：Mono- and diglycerides of fatty acids (MDGs) are commonly used in the production of sponge cakes due to their ability to form inclusion complexes with amylose, which prevents staling. They are considered as food additives and have to be mentioned on the ingredient list. The aim of this study was to use an enzymatic strategy in order to generate in situ mono- and diglycerides of fatty acids, starting from rapeseed oil and a non-GMO lipase through emulsification. Reaction products were first characterized by Gas Chromatography (GC). Proton Nuclear Magnetic Resonance (H-1 NMR) was employed as an additional technique to qualify and selectively identify the monoglyceride isomers. After 2 h of lipolysis, a high amount of MDGs was reached. Beyond this point, a continuous decrease was observed until 24 h. When used in total substitution of rapeseed oil, modified oils (2 h or 24 h) impact negatively the structure of cakes and have to be diluted before use. The structure and the softness of the products were characterized and followed up to 6 months. The best results were obtained with a 24-h enzymatic reaction and by diluting between 5 and 25 g/100 g in unmodified rapeseed oil.
查看更多>>摘要：Volatile compounds largely contribute to the aroma of raw pu-erh tea (RPT). However, the changes of volatile composition during manufacturing are unclear. This work characterized 58 volatile compounds in the RPT samples collected from withering, de-enzyming, sun-drying, and autoclaving-compressing stages. Results show that de-enzyming and autoclaving-compressing have large effects on the volatile composition, with the total volatile contents sharply decreased by 76.68% and 35.77%, respectively. After de-enzyming, the relative content of aldehydes increased by 4.68-fold, whereas that of alkenes decreased by 2.65-fold; thus, the attractive fatty aroma must be enhanced while weakening the unpleasant grassy aroma. The volatile composition would be greatly changed by autoclaving-compressing, which is a special step for RPT production but rarely studied before. These findings revealed the changes of the volatile composition of RPT during manufacturing, especially de-enzyming and autoclaving-compressing, which are important for the formation of the aroma characteristics of RPT.
查看更多>>摘要：Previously, the aroma compounds in watermelon juice were analyzed by either GC-MS or GC-O. These methods could not extract and analyze the volatile compounds comprehensively. Compared to the previous studies, for accurately identifying the aroma profile, the volatile compounds in fresh watermelon juice (FW) and thermally treated watermelon juice (TW) were analyzed using HS-GC-IMS and GC x GC-O-MS. Twenty-three compounds were detected by HS-GC-IMS, among them, allyl methyl sulfide, acetoin, and pentanal were identified for the first time in TW. Through GC x GC-O-MS analysis, 130 and 140 compounds were detected in FW and TW, respectively, and 36 and 38 of these compounds were smelled. In this study, 2,6-dimethyl-5-heptenal was identified for the first time in FW as an odor-contributing compound. These two kinds of juices could be differentiated by heat-mapping. The concentrations of (E)-2-decenal, decanal, 2-hexenal, 2-pentylfuran, and 6-methyl-5-hepten-2-one increased greatly by Volcano plot, and they contributed to the off-flavor in TW. For aroma analysis of watermelon juice, HS-GC-IMS can rapidly analyze the samples with low detection limits without pretreatment, while GC x GC-O-MS can precisely identify the compounds with sniffing. The results of this study suggest that HS-GC-IMS and GC x GC-O-MS can analyze the aroma profile more comprehensively and discriminate FW and TW more efficiently.
Gupta, AntimaSethi, SwatiYadav, D. N.Snigdha, Sneha...
9页
查看更多>>摘要：Khesari dhal (Lathyrus sativus L) or grass pea is one of the richest source of protein among pulses, however its utilization is limited owing to the presence of a neurotoxin i.e. beta-Oxalyl-di-amino propionic acid (beta-ODAP). beta-ODAP is a water soluble neurotoxin, hence, aqueous extraction of protein followed by isolation through precipitation may reduce/remove its concentration in protein isolates. . This study was aimed to optimize the process parameters for production of protein isolates from Khesari dhal (var. Mahateora). Four process parameters i. e extraction pH (8-10), extraction duration (40-80 min), extraction temperature (40-60 degrees C) and salt (sodium chloride) concentration (0.1-0.3%) were selected. Experiments were designed using response surface methodology (RSM) and executed accordingly. Maximum protein extraction (94.66%), recovery (81.04%), yield (23.10%) and purity (92.91%) was obtained at, pH 9; extraction duration, 58 min; temperature, 53 degrees C and salt concentration of 0.2% at khesari dhal: water ratio of 1:10. beta-ODAP was not detectable in protein isolates and functional properties namely protein solubility, foaming and emulsification capacity, water and oil absorption capacity and least gelling concentration were at par with other legumes protein isolates.
查看更多>>摘要：The effect of ancient grain pasta composition on its sorption properties and phase transitions was evaluated. Three pasta samples were prepared from ancient grain flours: spelt wheat, einkorn wheat, emmer wheat and quinoa, and for comparison purposes one pasta sample from durum wheat flour. Water adsorption and desorption isotherms of pasta were determined and they were fitted by the Guggenheim-Anderson-de Boer equation. The state diagrams of pasta samples were developed by measuring their freezing points, glass transition temperatures, and the maximum-freeze-concentration conditions by Differential Scanning Calorimetry. All the pasta samples exhibited sorption hysteresis with higher equilibrium water content determined for desorption. Substitution of spelt wheat flour with other ancient grain flours in pasta samples resulted in decreased glass transition temperature, freezing temperature and the end point of freezing. The amount of un-freezable water in ancient wheat flour-based pasta was significantly higher than in durum wheat pasta. The results showed that the modification of chemical composition of pasta as a result of replacing semolina with flours from ancient grains is accompanied by a change in their sorption and thermal properties.
Cifuentes, AlejandroFerreira, Sandra R. S.Gutierrez, Luis-FelipeSanchez-Camargo, Andrea del Pilar...
12页
查看更多>>摘要：This work includes the second/sequential stage of a green-based valorization strategy of mango peel. An exhausted biomass from a pilot-scale CO2 supercritical extraction process was reused for obtaining phenolic-rich extracts with high antioxidant and anti-proliferative activity, employing microwave-assisted extraction. The effects of microwave power (400-800 W), liquid-to-solid ratio (10-50 mL/g) and extraction time (60-120 s) on process yield, phenolic content, and antioxidant capacity were investigated using a Box-Behnken design. A solution consisting of 60% aqueous ethanol was used as extraction solvent. The results showed that microwave power and liquid-to-solid ratio were the most influential factors on the responses variables. The highest total phenolic content (52.08 mg gallic acid eq./g d. w.) and antioxidant activities (2.75 mmol trolox eq./g extract, and of 6.47 mu g/mL expressed in DPPH, EC50) were obtained at 800 W, 50 g/mL, and 90 s. Mango peel extract recovered at optimal conditions provided high anti-proliferative activity against HT-29 colon cancer cells line, after 24 h treatment (IC50 = 22.98 mu g/mL). Gallic acid derivatives, such as galloyl-esters, xanthones like mangiferin, flavonoids, including quercetin and quercetin glycosides were tentatively identified by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Most probably, the compounds responsible for the outstanding anti-proliferative activity.
NSTL
Elsevier