Wang, Yao-YaoYan, Jing-KunDing, YanhuaRashid, Muhammad Tayyab...
8页
查看更多>>摘要：The effects of sweep frequency ultrasound thawing (SFUT) and fixed frequency ultrasound thawing (FFUT) on the water holding capacity (WHC), strength, color, rheological properties as well as moisture migration and distribution of myofibrillar protein (MP) gel from small yellow croaker (Larimichthys polyactis) were evaluated. The results showed that the MP gel from the SFUT sample had a smaller chromatic aberration (Delta E) (12.39), higher WHC (65.05%) and strength (101.03 g) than the MP gel from FFUT and flow water thawing (FWT) samples. Compared with FFUT and FWT groups, the MP gel from the SFUT sample had higher elasticity and smaller apparent viscosity. Meanwhile, the MP gel from the SFUT sample had higher immobilized water content and lowered free water content close to the fresh sample (FS). Overall, the MP gel from the SFUT sample had better gelling properties than the MP gel from the FFUT and FWT groups.
查看更多>>摘要：Flavonoids are a ubiquitous group of phytochemicals with diverse bioactivities. They are widely distributed in numerous plant-based foods with potential health benefits. Humans directly consume flavonoid-rich foods or ingest them after food processing or cooking. These processes may exert either a positive or negative impact on the stability and bioactivity of flavonoid compounds. In this review, the impacts of different food processing methods on flavonoid contents in various food sources were systematically summarized. Moreover, the influence of the structural characteristics on the stability of flavonoids was also discussed. Notably, according to the recently reported studies on flavonoid-rich foods subjected to some nonthermal treatments, the increased retention of flavonoid contents and improved antioxidant activities can be found. The current review focusing on variations of flavonoids under different processing conditions can provide a theoretical reference for maintaining flavonoid compounds in the food matrix during food processing.
查看更多>>摘要：Although active peptide is an important functional component, the mechanism of releasing peptides promoted by the degradation of tea protein during fermentation is still unclear. The profiles of peptides and tea proteins in pickled tea during anaerobic fermentation were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results showed that water-soluble proteins are the main target of hydrolysis in the fermentation, and the degradation of tea protein clusters at different fermentation time triggers the continuous release of peptides. ILW, WLR, WY, YV, ELW, FY, and PYV are considered to be the key peptides related to the antioxidant activity of pickled tea, and enzyme proteins especially rubisco and tubulin family proteins may be responsible for the release of these potential antioxidant peptides. Peptides derived from tea proteins are suggested to be one of the key antioxidants in pickled tea. The findings can promote to targeted degradation of tea protein to increase the active peptides and function in microbial fermented tea.
查看更多>>摘要：Despite intensive studies on 4D printing to induce evolutions of various properties of foods, limited information exists on the use of this technology to allow nutritional changes of printed foods. Here, ergosterol was incorporated into purple sweet potato pastes, which served as the base material for 3D printing; 4D printing was realized through UV-C irradiation to convert ergosterol into vitamin D2. Experiments were first conducted to compare printability of the pastes of different compositions. Maximum amount of ergosterol that could be added was determined. Schemes to allow minimal use of printing materials, while enhancing the conversion of ergosterol into vitamin D2 were also proposed. Pastes with ergosterol concentrations lower than 0.65 mg/g could be well printed. Reducing internal filling ratio was noted as an effective means to improve the conversion. When such a ratio was 70%, more formation of vitamin D2 at minimal use of raw materials could be realized.
查看更多>>摘要：This study investigated the effects of air, microwave (MW), and vacuum microwave (VMW) thawing treatments on the physical properties of frozen apples, including weight loss, electrical impedance characteristics for assessment of cellular structure, surface color, and mechanical properties, as well as the heating uniformity in MW and VMW thawing. The results showed that VMW inhibits the localized overheating of the sample during thawing compared to MW thawing. VMW thawing increased the breaking strain of the sample tissues compared to the other samples. The breaking stress and maximum stress, which are indices of the hardness of the tissue, were significantly reduced after freezing-thawing in each thawing method; the phenomenon was thought to be caused by the damage to the cell structure, which was confirmed by the electrical impedance analysis. The level of browning was significantly lower in MW and VMW thawing than in air thawing at 20 degrees C because they required a relatively short thawing time. This study showed that one of the specific effects of VMW thawing is that it can thaw the sample in a short time by inhibiting excessive heating and localized heating, indicating its potential for application as a high-quality and efficient thawing technology for various foods.
查看更多>>摘要：This study aimed to investigate the effects of pulsed electric field (PEF), ultrasound (US), and combined pre treatments (PEF-US) on mass transfer, rehydration capacity, microstructure, and nutritional quality of shiitake mushrooms (Lentinus edodes). The results indicated that pretreatments could accelerate mass transfer during the hot-air drying process at 65 degrees C, resulting in lower drying time and energy requirement than control. Meanwhile, the low-field nuclear magnetic resonance (LF-NMR) analysis revealed better rehydration capacity of the pretreated groups than the untreated group. The results of scanning electron microscopy (SEM) demonstrated that pretreatments significantly changed the cell structure by developing intracellular space and larger cavities and facilitating the drying and rehydration process of mushrooms. Additionally, the physiochemical analysis illustrated that pretreatment could preserve the color and nutritional quality more effectively than the untreated groups. Of the pretreatment groups, the shortest drying time was observed in the combined (PEF-US) group (4.7 h). The PEF-US pretreated mushroom also exhibited the highest phenolics (224.17 mu g/mu L) and soluble sugar (3.90 mg/mL) levels. Overall, the study concluded that the combined pretreatment group (PEF-US) was a promising pretreatment method for hot-air drying of mushroom products to improve the drying efficiency, product quality control, and nutritional value protection.
Kyriakopoulou, KonstantinaRahmani, AfinaVenema, Paulvan der Goot, Atze Jan...
10页
查看更多>>摘要：In this study, we investigated the effect of isochoric moisture heating on the functionalities of simply fractionated soy protein. Soy protein-rich fractions (SPFs) were produced through a simplified wet fractionation process, in which the defatting and intensive washing steps were omitted. After a neutralization step, the protein-rich dispersions were heated up to various temperatures ranging from 60 to 100 degrees C and subsequently freeze-dried. It was found that the denaturation level, the water holding capacity and the viscosity of SPFs increased as the processing temperature rose, whereas the solubility of SPFs decreased. Additionally, among the different conditions, an intermediate heating temperature of 70 degrees C resulted in SPFs having a gel network with the highest elasticity. Overall, isochoric moisture heating coupled to simplified fractionation can be used to precisely control the functionality of soy protein ingredients with mild heating conditions. This work provides insights on the production of ingredients with desired functionality for novel soy-based applications like soy meat analogues.
查看更多>>摘要：The Almagro eggplant is a vegetable used in a traditional pickle made in Spain through a natural process of fermentation for several days in a brine solution. The aim of the present work was to study the population of yeast present in fruits and brines during the industrial processing of Almagro eggplants in two different factories. Total yeast counts obtained in factory A were about 7-8 log CFU/mL, with slightly lower values determined for the fruits. In contrast, in factory B the counts were lower than 2 log CFU/mL with the highest values found in the post-fermentative stage. From a total of 380 isolates only eight different species were identified. In factory A the major species was Pichia occidentalis (82%). In addition, Kazachstania exigua, K. unispora and Zygosaccharomyces bailii were also isolated. In factory B the main species isolated was Candida ethanolica (40%) followed by Pichia kudriavzevii, Issatchenkia orientalis, P. occidentalis and P. manshurica. Only intraspecific differences for P. mashurica were found by RAPD-M13. The results provided a valuable information on yeast population biodiversity and dynamics in the naturally fermented Almagro's eggplants pickles.
查看更多>>摘要：This study aimed to evaluate the antibacterial activity and mechanism of action of Aronia melanocarpa anthocyanins (AMAs) against Escherichia coli. AMAs displayed strong antibacterial activity against Escherichia coli. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AMAs against E. coli was 0.625 mg/mL and 1.25 mg/mL, respectively. Analysis of alkaline phosphatase activity, potassium ion leakage, absorption material release at 260 nm, and change in soluble protein content revealed that AMAs could destroy the cell wall and membrane structure of E. coli. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) further confirmed the cell wall and cell membrane damage induced by AMAs. In addition, the interaction between AMAs and DNA was elucidated through agarose gel retardation and fluorescence spectroscopy. In summary, the present results indicate that AMAs kill E. coli by attacking multiple targets in the bacterial cell, which could favour the application of AMAs as natural food preservatives.
查看更多>>摘要：This study used partial least squares regression (PLSR) to explore the evolution of the oxidative characteristics (peroxide value, p-anisidine value, conjugated diene value), antioxidant capacity (DPPH and ABTS assays), fatty acids, bioactive compounds (tocopherols, squalene, carotenoids and phytosterols) and free radicals in hazelnut oil during accelerated oxidation for 40 days. After 25 days of oxidation, hazelnut oil entered a highly oxidative state; as radicals began to be heavily generated, the antioxidant capacity decreased significantly. The contents of tocopherols, squalene, carotenoids, linoleic and linolenic acid were significantly reduced, which was significantly negatively correlated with the oxidative degree of hazelnut oil. In addition, electron spin resonance (ESR), which is an effective nondestructive method of measuring radicals, could be used online to detect the oxidative degree of hazelnut oil. Carotenoids and tocopherols play important roles and may be provide effective selection of the natural antioxidants to prevent hazelnut oil oxidation.
NSTL
Elsevier