查看更多>>摘要：Geobacillus stearothermophilus spores play an essential role in the pharmaceutical and food industries as bioindicators (BI) to evaluate inactivation effects of hydrogen peroxide in processing and packaging lines' sterilization. Unstandardized, inconsistent BI production, as is the case for currently available commercial BI, can lead to variable resistances and incorrect test results. The solution to this problem could be the standardization of BI spore production. This study assessed the effects of sporulation temperature and pH on spore resistance in the production of G. stearothermophilus ATCC 7953 spores on solid-state agar. For this purpose, spores were produced under different sporulation conditions (51-63 degrees C, pH 6-8), and their resistance was determined by the D-value in 35% liquid hydrogen peroxide at 25 degrees C. Based on these data, a mathematical equation describing the resistance as a function of the sporulation conditions was derived. The analysis showed a quadratic effect of the sporulation temperature and a linear effect of the examined domain's pH on the resistance, without interactions between these factors. We observed the highest D25C,35%H2O2-value of 309 s at sporulation conditions of 57 degrees C and pH 6.0.
查看更多>>摘要：Bread staling is a deterioration process that causes serious economic losses in the food industry. The objective of this research was to determine the impact of Laminaria japonica polysaccharides (LJP) on the anti-staling properties during storage. The baking, thermal, starch retrogradation, and microstructure properties of bread with LJP during room storage were investigated. The results showed that the addition of LJP improved specific volume and textural properties. The kinetic model showed that the addition of LJP decreased the rate constant. Meanwhile, LJP addition exhibited a significant decrease of enthalpy and crystallization in the frozen dough bread. Data also showed that LJP may form more hydrogen bonds and interfere the starch reassociation and retrogradation. This effect was also evident in the microstructure, showing that LJP could improve the fresh quality and delay the deterioration of the bread structure. Overall, LJP can potentially be used as an effective natural additive to increase the storage stability of baked food.
查看更多>>摘要：Edible grade rice bran oil (RBO) rich in gamma-oryzanol and phytosterol but without glycidyl esters (GEs) and monochloropropanediol esters (MCPDEs) was obtained from rice bran by moderate biorefining. High-acid RBO (acid value of 51.22 mg KOH/g) was firstly extracted from rice bran and was then moderately biorefined by combining improved enzymatic degumming, dewaxing, enzymatic deacidification, bleaching, and lowtemperature purification (120 degrees C). Through monitoring the refining process, results showed that the improved enzymatic degumming by combining partial glyceride lipase SMG1-F278N and phospholipase A1 enabled the phosphorus content to quickly decrease to 4.56 mg/kg after optimization by response surface methodology. After biorefining, the final RBO with the acid and peroxide value of 0.10 mg KOH/g and 2.05 mmol/kg reached the grade-one standard of edible oil. Additionally, the final RBO contained 20.66 mg/kg gamma-oryzanol and 20.63 mg/kg phytosterol with the retention rate of 71.67% and 59.2% but with undetectable GEs and MCPDEs. The environmental friendliness of the novel moderate biorefining process and superior product quality of the final product point toward a promising viable process for RBO refining in the further.
查看更多>>摘要：This paper focused on application of nanofiltration (NF) for improving fish sauce quality by enhancement of content of nitrogen compounds. Three kinds of NF membranes, including NF99, Desal DK and NTR7250, were investigated into separation capacity of total nitrogen (TN), amino nitrogen (AN) and NaCl from fish sauce. The influence of pretreatment of fish sauce by ultrafiltration (UF) on fish sauce quality was also investigated. Desal DK membrane exhibited the good performance for NF of fish sauce. UF pretreatment improved the rejections, except NaCl, and permeate flux. The NF of UF pretreated fish sauce with Desal DK membrane was also carried out at 40 bar of operating pressure. At 3.21 of concentration factor (CF), comparing to raw fish sauce, content of TN and AN increased by 2.21 and 2.11 times, respectively; whereas, content of NaCl increased approximately 5%. Results indicate that NF is a potential method for improvement of fish sauce quality. Hermia's model was applied to interpret the fouling phenomenon occurring in NF of UF pretreated fish sauce. The results showed that the best fit to experimental data corresponds to cake layer formation model. The excellent fitting between the experi-mental and calculating data for enhancement of fish sauce by NF was observed.
查看更多>>摘要：The effect of an active package (AP) based on rice bran extract (RBE) with antioxidant and antimicrobial activity was studied in combination with high hydrostatic pressure (HPP) aiming to preserve sliced vacuum packaged Iberian dry-cured ham. For that matter. four different assays were carried on: AP, HPP, AP + HPP and a control group with any treatment. The packages were treated by HPP at 600 MPa for 7 min in order to increase the microbiological safety of the dry-cured product. Microbiological and quality changes after processing and during storage at two temperature conditions (4 and 20 degrees C) were evaluated for long times of storage: 90 days (4 and 20 degrees C) and 180 days (4 degrees C). The active packaging based in RBE and HPP were effective against some microorganisms (mesophilic aerobic and moulds and yeast) when the samples were stored at refrigeration. Active packaging reduced lipid oxidation development in long storage times (180 days) from 2.1 mg MDA kg(-1) in control to 1.7 and 1.8 mg MDA kg(-1)in RBE and RBE + HPP, respectively In any case, the treatments carried out do not decrease the sensory quality of the sliced dry-cured Iberian ham, which highlights their potential application in the industry.
查看更多>>摘要：Yeast fermentation represents a novel strategy to modulate tea aroma compound formation due to its various metabolic activities. A selected non-Saccharomyces yeast Cyberlindnera (formerly Williopsis) saturnus var. mrakii NCYC 2251 was used to ferment green tea slurry. Meanwhile, 13-glucosidase activity of C. mrakii NCYC 2251 was determined. The 13-glucosidase activity assay of C. mrakii NCYC 2251 revealed a positive correlation between yeast biomass (cell count) and 13-glucosidase activity. GC-MS analysis of yeast-fermented and 13-glucosidasetreated tea slurries showed that some glycosylated aroma compounds such as methyl salicylate, benzyl alcohol and 2-phenylethanol increased with the passage of fermentation time. Whereas, the increases of these compounds in 13-glucosidase-treated tea slurries exhibited dose-dependent trends. These results demonstrated the effects of yeast 13-glucosidase on tea aroma compound formation during fermentation.
查看更多>>摘要：This study investigated the effect of high-pressure homogenization (HPH) (0, 20, 40 and 60 MPa) on the emulsifying properties and structural changes of chicken liver (CL) proteins isolated by isoelectric solubilization/ precipitation (ISP) (with the acid/alkaline solubilization at pH 2.0, pH 3.0, pH 11.0 and pH 12.0 respectively and the precipitation at pH 5.5). Results showed that HPH could significantly decrease the particle size. With the increase of homogenization pressure, the solubility of the same ISP-isolated CL-proteins increased significantly and that of alkali-isolated proteins was the highest (P < 0.05). The preferable emulsifying activity index (EAI) and emulsifying stability index (ESI) were obtained at pH 11.0 after 40 MPa treatment (reaching 34.90 m2/g and 37.77% respectively), which appeared the highest creaming layer. Compared with other treatments, the corresponding same ISP-isolated CL-proteins at 40 MPa HPH had highest surface hydrophobicity index (H0) and free sulfhydryl content. After HPH, Raman spectroscopy revealed that the same ISP-isolated CL-proteins presented a decrease in alpha-helix accompanied by the increase of the beta-sheet to be beneficial to the formation of stable emulsion. This study showed that suitable HPH combined with ISP treatments promoted the emulsifying stability of proteins.
Chakka, Ashok KumarSriraksha, M. S.Ravishankar, C. N.
14页
查看更多>>摘要：The food industry is dynamic. The needs and necessities of the consumer keep changing, and it becomes inevitable for the industry to fulfil those needs and eventually grow with them. In recent years, the food industry has grown immensely and has a greater market value. Nevertheless, on the flip side, it cannot go unnoticed that the food industry is one of those industries having a considerable impact on the environment. This alarming situation has led to the development of various green, sustainable technologies over the years, which can reduce the energy consumption that goes into the production, processing and packaging of food. This review focuses on five such green, nonthermal technologies: pulsed electric field, high-pressure processing, cold plasma, ozone, and electrolysed water. This review also discusses the sustainability and impact of each of these technologies on food products/materials.
Zhu, YaoWang, JinVanga, Sai KranthiRaghavan, Vijaya...
10页
查看更多>>摘要：Eggs are one of the most common ingredients used by human beings due to their nutritional attributes and health benefits. However, eggs also contain an anti-nutrient known as avidin, which forms an avidin-biotin complex, resulting in biotin unavailable in the body for absorption. In the present study, molecular dynamics (MD) simulation was used to evaluate the effect of external stresses, including thermal and oscillating electric field (0.05 V/nm, 2450 MHz) at 300-353 K on the structural properties of avidin. The modeling was performed using a GROningen MAchine for Chemical Simulations (GROMACS) software. The alteration in conformation of avidin was evaluated in terms of the number of hydrogen bonds, root mean square deviation, the radius of gyration, and solvent accessible surface area. The application of thermal stress and electric field resulted in conformational changes in the avidin protein. The results also showed that hydrogen bonds have a significant influence on the stability of alpha-helices, which are responsible for the compactness of the molecule. Change in the hydrogen bonds can increase the surface area and hence the surface properties of avidin significantly. Thermal combined with electric field showed an application in inhibiting the activity of avidin present in egg white.
查看更多>>摘要：The increasing health awareness among population has resulted in demand for foods with minimum side effects. In recent times, natural biomolecules are more preferred as compared to their synthetic counterparts. Microbial polysaccharides have shown potential to replace synthetic food additives. The present study aims to explore marine exopolysaccharide (EPS) as a replacement for synthetic emulsifiers such as sorbates and polysorbates. In the process, an EPS designated as K1(T)-9 was isolated from the marine bacterium Neorhizobium urealyticum K1(T) sp. nov. that showed pH stable emulsification activity. This EPS K1(T)-9 was utilized as an emulsifier for nanoemulsion formation through ultrasonication to encapsulate and enhance the bioavailability of astaxanthin. Partial characterization of the EPS suggested that it is a heteropolysaccharide consisted of glucose and galacturonic acid with a molecular weight of 207 kDa. Interestingly, the functional properties of K1(T)-9 have revealed that the molecule exhibited non-Newtonian pseudoplastic and shear-thinning flow behavior along with high water (356 +/- 0.8%), oil holding (697 +/- 1% for coconut oil, and 317 +/- 1.3% for olive oil), and swelling capacity (200 +/- 1.1%). Thus, the EPS K1(T)-9 obtained from Neorhizobium urealyticum sp. nov. holds plausible applications in food and related industries.
NSTL
Elsevier