查看更多>>摘要：Phospholipids can act as antioxidants and prooxidants, and they themselves can generate an abundance of lipidderived volatile compounds. Homogenized pig subcutaneous adipose tissue was extracted by ethanol to remove phospholipids, then the partly de-phospholipids adipose tissue and adipose tissue were dry-rendered, and the volatiles in lard samples were analyzed. Most of lipid-derived odorants, such as (E,E)-2,4-decadienal and 1-octen3-ol in the conventional dry-rendered partly de-phospholipids lard were higher than those in the conventional dry-rendered lard. In addition, the results of sensory analysis were agreed with the contents of odorants. A comparison between solvent extracted lard and solvent extracted lard with additional pork phospholipids in a simulating dry rendering process was performed to demonstrate the influence of phospholipids, and the results confirmed that pork phospholipids decreased lipid-derived volatiles of lard in dry rendering process. The results of peroxide values and thiobarbituric acid values also proved that pork phospholipids acted as antioxidants to inhibit the oxidation of lard, which could be of great potential use to catering, oil and fat industry.
查看更多>>摘要：Incorporation of A. auricula into wheat flour dough could improve their nutritional properties, but utilization of A. auricula is limited as it causes a weakened dough and deterioration in the quality of product. In this study, A. auricula was treated using high temperature high pressure processing combined with acidic solution treatment, and the effect of A. auricula before and after the treatment on the rheological and structural properties of dough was investigated. Results showed that the high temperature high pressure-acidic solution treated A. auricula (HTHPA) did not block the formation of intrachain disulfide bonds in glutenins. On the contrary, it led to a higher aggregation extent of glutenin macropolymer by contributing to the crosslinking of proteins via noncovalent interactions. Rheological tests showed that the doughs with 2-8% HTHPA exhibited higher elastic and viscous moduli and shear-thinning behavior compared to the doughs with 2-8% untreated A. auricula (UA). This will contribute to the volumetric expansion of dough during proofing. Temperature sweep test revealed that addition of 2-8% HTHPA could reinforce the intermolecular interactions in the dough structure. This study will provide a new method to design and produce A. auricula-enriched staple foods with desirable rheological and structural properties.
Ben Hammouda, MounaMahfoudhi, AmiraGharsallah, HoudaEl Hatmi, Halima...
9页
查看更多>>摘要：Grape (GV), fig (FV), prickly pear (PPV) and date (DV) vinegars are the most popular Tunisian homemade vinegars. Throughout the present study, we investigated the diversity of these fruit vinegars in terms of their physicochemical, microbiological and biological properties, as well as their phytochemical profiles. Despite a great variability between their characteristics, all vinegar samples showed significant total phenolic and flavonoid contents which ranged from 286.36 to 1636.75 mg GAE/L and from 240.58 to 755.84 mg QE/L, respectively. Through the evaluation of their antioxidant activity via DPPH, iron reducing antioxidant power (FRAP) and metal chelating assays, all vinegar samples showed important antioxidant potential which could be associated with their richness in phytochemical compounds. Indeed, 19 phytochemicals were identified using LC-MS, with the most abundant being quinic, protocatchuic, p-coumaric, and transferulic acids. Antimicrobial activity of vinegars was tested against Gram-positive and Gram-negative bacterial strains as well as against fungal strains. Results revealed that most of vinegar samples were found to be more inhibitive against bacterial strains than against fungal ones. Overall, these results indicated the high potential of Tunisia homemade fruit vinegars as antioxidant and antimicrobial agents that could be used as functional food ingredients.
查看更多>>摘要：The interaction of proteins with anthocyanins (ACNs) gives rise to significant improvements in their functional properties. To explore the interactions between whey protein isolate (WPI)/bovine serum albumin (BSA) and blueberry ACNs, light (5000 Lux, 7 days), heat (85 degrees C, 2 h), sucrose (0.25 mg/mL), and vitamin C (0.15 mg/mL) were used to accelerate the degradation of ACNs. Through the observation of color changes and variations in the free radical scavenging rates, WPI and BSA were found to protect the ACNs to varying degrees. Moreover, WPI/ BSA exhibited increased solubilities, foaming and emulsifying properties, and changed thermal stabilities and protein structures, in addition to decreased surface hydrophobicities and zeta potentials. Furthermore, the addition of WPI/BSA increased the number of ACN monomers in a simulated digestion system, as determined by high-performance liquid chromatography-mass spectrometry. Therefore, by studying the interactions between proteins and ACNs, we can provide a strategy and theoretical basis for determining the steady-state of ACNs in blueberry products.
查看更多>>摘要：The thermostability of carotenoids and capsaicinoids in a butter model (B), a rapeseed oil model (RO) and a blended model (BRO) was investigated under heating at 120-180 degrees C. The kinetic deterioration rate of each compound was described by a first-order kinetic model, while changes in L*, a*, and b* values were fitted to a zero-order model. Moreover, based on activation energy (Ea), the most and least temperature-sensitive oil models were B and RO, respectively. Across all oil models, carotenoid rate constants could be ordered as kcap-santhin > k(zeaxanthin) > k(beta-cryptoxanthin) > k(beta-carotene) > kcapsorubin, and color index values could be ordered as k(a) > k(b) > k(L). The Ea values of capsaicin and dihydrocapsaicin in RO were 52.77 and 51.78 kJ/mol, respectively. Our results suggest that the stability of carotenoids and capsaicinoids can be influenced by the oxidizability and antioxidant content of oil.
查看更多>>摘要：Zygosaccharomyces rouxii is an osmotolerant yeast that is responsible for the spoilage of high sugar content foods. Microwave heating technology is used as an alternative to conventional pasteurization. Main purpose of this research was to determine the thermal resistance of Z. rouxii in organic intermediate moisture content (IMC) fruits (apricot and fig) during the microwave pasteurization process and comparing the D, z and F values with the conventional method. F85 values were calculated both theoretically and experimentally. Additionally, the effects of the pasteurization methods on the quality properties (total soluble solid, pH, acidity, water activity, moisture content, rehydration capacity, weight loss, hydroxymethylfurfural (HMF) and color) of the samples were investigated. The results show that come up time (CUT) and D values were significantly reduced by microwave treatment. The yeast reached a five log10 reduction by the microwave heating method with the F8533.8 value of 3.6 min for apricot and F8532.15 value of 3.35 min for fig. Total soluble solids, weight loss, and color values were preserved better in microwave pasteurization than the conventional method in both samples. Hydroxymethylfurfural content of the microwave pasteurized samples was 23.5% and 32% less than the samples pasteurized conventionally for apricot and fig samples, respectively.
查看更多>>摘要：Diafiltration had been widely used in milk protein fractionation for almost thirty years to produce caseinenriched retentate. Among them, intermittent feed diafiltration was the only way ever used. But we noted some other diafiltration types had been used in other fields such as chemical engineering. In this study. The separation performance, chemical properties, component resistance and mass balance analysis were compared under different diafiltration types, aiming to find suitable diafiltration processes for milk protein fractionation. Research suggested that different diafiltration process may have different advantages. From the separation performance point of view, the highest removal rate of native whey proteins was observed under variable volume diafiltration (VVD) mode. But in terms of average flux, constant volume diafiltration (CVD) mode was utmost time and energy saving with an average flux of 81.25 kg m(-2)h(-1). In addition, the percentage loss of protein under CVD and constant volume concentration ratio diafiltration (CVCRD) mode were significantly lower than that of other diafiltration modes (P < 0.05), indicating fewer protein were absorbed or compacted by the membrane. Therefore, diafiltration type should be selected according to the purpose of production.
Lopez-Vega, L. A.Gil-Cortez, J. M.Sierra-Sarmiento, M. A.Hoyos-Leyva, J. D....
6页
查看更多>>摘要：Hass avocado (Persea americana Mill. var. Hass) oil is a product of interest due to its functional properties and human health benefits. Physiological (P), consumption (C), and overripe (OR) stages of maturity were analyzed to establish the postharvest time to oil extraction. The OR has 19.2 +/- 1.2/100 g oil content, with a hardness of 17.6 +/- 0.6 N. A 3(3-1) fractional experimental design was proposed to analyze the optimal conditions of the malaxation process as a pretreatment for oil extraction. From the response surface analysis, a statistical model was reported to predict the oil extraction efficiency, and the time and temperature variables showed an optimal point. The highest extraction efficiency under the conditions evaluated was 48.9 degrees C temperature, agitation speed 49.7 rpm, and time 92.6 min, which yielded an extraction efficiency of 77.6 +/- 0.08 g/100 g. The physicochemical characterization of the oil indicated an acid value of 0.4 +/- 0.7 g/100 g, peroxide index of 18.5 +/- 0.7 mEqO(2)/kg, and iodine index of 76.7 +/- 1.0 g I-2/100 g with a relative density of 0.915 g/ml which showed that the optimized malaxation process conditions did not affect the final Hass avocado oil quality.
查看更多>>摘要：This study was dedicated to the functionalization of soya press cake (SPC) by ultrasonication and fermentation to produce wheat bread enriched with okara nutrients. Different frequencies (18 & 850 kHz) ultrasound (US) was used for the treatment of SPC. The application of low-frequency US resulted in 80.64 and 58.06% higher contents of soluble proteins (SP) and soluble dietary fibre (SDF), respectively. The content of SP with high-frequency US treatment was increased by 64.51% and a significant increase in SDF content was found. The application of soya meal and SPC treated with low-frequency ultrasound as fermentation media resulted in a higher lactic acid bacteria (LAB) cell number and enhanced production of L-lactic acid. By adding 5% of sonicated and fermented SPC for wheat bread production, a higher porosity of bread crumb and specific volume was achieved, compared to breads with other soya ingredients. Novel method - emotional response to the products was applied in order to evaluate acceptability of final breads. Comparing breads enriched with okara, highest acceptability score (7.2) was achieved using 5% of sonicated and fermented SPC. The results of this study showed potential improvement in functionality of wheat bread supplemented with okara dietary fibre.
查看更多>>摘要：Daqu is the natural mixed starter culture for special-flavour Baijiu (the unique famous Baijiu in Jiangxi Province) brewing. Peak-temperature effects of Daqu on chemical compositions, microbial community succession and volatile substances in Jiupei fermented with middle peak-temperature Daqu (MTJP) and Jiupei fermented with high peak-temperature Daqu (HTJP) during special-flavour Baijiu brewing were determined. It was found that ethanol and reducing sugar had significantly (P < 0.05) higher contents in MTJP than HTJP. Peak-temperature of Daqu had a greater impact on the fungal community than the bacterial community in Jiupei. The total content of volatile substances in HTJP was 1.5-3 times of those in MTJP during fermentation. Most esters were positively correlated with Pichia, Lactobacillus and Bacillus genera in HTJP, but positively correlated with Aspergillus, Monascus, Pichia and Lactobacillus genera in MTJP. In a word, middle peak-temperature Daqu (MT Daqu) could enhance the ethanol production through Aspergillus genus with high glucoamylase activity and high peak-temperature Daqu (HT Daqu) could enhance the accumulation of volatile substances through more abundant flavour-producing microorganisms. Our study have provided theoretical basis for the further research on peak-temperature of Daqu effects on the quality of various Chinese Baijiu.
NSTL
Elsevier