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1.
Oxidation of sarcoplasmic proteins during processing of Cantonese sausage in relation to their aggregation behaviour and in vitro digestibility 总被引:3,自引:0,他引:3
The physicochemical changes of sarcoplasmic proteins, especially oxidation behaviour, were measured to determine their mechanism of action on in vitro protein digestibility during Cantonese sausage processing. The results indicated that carbonyl level increased (p<0.05) during the process. The fluorescence loss of tryptophan residues was a direct consequence of the oxidative degradation. All the parameters of protein aggregation were highly (p<0.05) correlated with carbonyl level and protein surface hydrophobicity (H(0)), indicating that protein oxidation and thermal denaturation could induce protein aggregation, leading to secondary structural changes. The analysis of in vitro digestibility showed no correlation between pepsin activity and protein oxidation, due to the biphasic response of sarcoplasmic proteins toward proteolysis. However, a highly significant (p<0.05) correlation was observed with trypsin and α-chymotrypsin activity, indicating that protein oxidation induced the changes in H(0), protein aggregation and secondary structure, which further influenced in vitro digestibility. 相似文献
2.
Cantonese sausage proteins were classified into five fractions based on solubility. The alkali-soluble protein was the major protein component of Cantonese sausage and increased during the process. The salt- (myofibrillar proteins) and water-soluble protein fractions (sarcoplasmic proteins), which decreased throughout the process, played an important role in the proteolysis. The total carbonyl content was found to significantly increase (p < 0.05) in sarcoplasmic, myofibrillar and alkali-soluble proteins. The SH group level decreased, whereas S–S group level increased gradually. The protein solubility determinations suggested that hydrogen bonds, hydrophobic interactions, disulphide bonds and ionic bonds gave rise to a three-dimensional network structure of Cantonese sausage proteins. Average particle size and specific surface area of Cantonese sausage proteins were affected by the changes in composition and oxidation of proteins. Results of proteolysis suggested that proteolytic susceptibility was influenced by the degree of protein oxidation. 相似文献
3.
The heat-induced aggregation and the in vitro digestibility of vicilin-rich protein isolates from three Phaseolus legumes, including kidney bean, red bean and mung bean were investigated and compared, and their amino acid composition and free sulfhydryl (SH) group contents also evaluated. The results showed that the extent in the heat-induced aggregation varied with the type of the protein isolates, and the formation of new disulphide bonds (at the expense of free SH contents) was involved in the formation of the aggregates. The protein isolates with higher levels of hydrophobic and uncharged polar amino acids, and lower basic amino acid contents exhibited lower extent of their heat-induced aggregation. The in vitro pepsin plus trypsin digestibility was different for various native protein isolates. The digestibility was to a varying extent affected by the heat treatment. The influences of heating on the digestibility of these proteins were closely related to the extent of their heat-induced aggregation. The results suggest that the improvement of nutritional property of those vicilin-rich protein isolates by heat treatment is largely dependent upon their amino acid composition as well as the extent of heat-induced aggregation. 相似文献
4.
Cross-linked carboxymethyl rice starches (CL-CMRSs) were prepared from reactions between native rice starch and varied concentrations (0.1–15% w/w, M-0.1 to M-15) of epichlorohydrin (ECH) in a simultaneous carboxymethylation-crosslinking reaction setup using methanol as the solvent. The degree of carboxymethyl substitution was between 0.24 and 0.28, while apparent amylose contents were lowered due to modification. SEM images showed minor change on the granule surface, while XRD profiles indicated slight loss of crystallinity. DSC thermograms revealed no transition peak in all treated samples. The water uptake (WU), swelling volume (SV) and free swelling capacity (FSC) of CL-CMRSs increased significantly as a result of the modification, while swelling of CMRSs cross-linked with 2% (M-2) and 3% (M-3) ECH yielded FSC values and WU values that were much greater than those of native starches and were comparable to that of Explotab®. All modified starch samples showed increased amount of rapidly digestible starch (RDS), while cross-linking with 5–7.5% ECH raised the resistant starch (RS) content, compared to native starch. M-2 also showed promising results in tablet disintegration test. ECH–CL–CMRSs could potentially be used as an excipient in pharmaceutical and food/food supplement products. 相似文献
5.
The effects of various domestic processing methods such as soaking, cooking and autoclaving on the levels of certain antinutritional factors and in vitro protein digestibility of seeds of Bauhinia purpurea L., an underutilised legume collected from South India, were investigated. The raw seeds were found to contain antinutritional factors like total free phenolics (2.75 g/100 g), tannins (2.35 g/100 g), phytic acid (692 mg/100 g) and flatulence factors, raffinose (0.54 g/100 g), stachyose (1.17 g/100 g) and verbascose (0.95 g/100 g). Soaking the seeds in distilled water caused maximum reduction in the phytic acid content (37%), whereas soaking in NaHCO3 solution reduced significant levels of phenolics and tannins (72% and 78%, respectively). A reduction in the levels of oligosaccharides (raffinose by 63%, stachyose by 42% and verbascose by 79%) was observed during cooking. Of the attempted treatments, autoclaving appeared to be most effective in reducing levels of all the investigated antinutrients, except phytic acid, and also improved the in vitro protein digestibility of B. purpurea seeds. 相似文献
6.
The protein constituents and thermal properties of hemp (Cannabis sativa L.) protein isolate (HPI) as well as 11S- and 7S-rich HPIs (HPI-11S and HPI-7S) were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and different scanning calorimetry (DSC), and their amino acid composition and in vitro digestibility were also evaluated, as compared to soy protein isolate (SPI). SDS-PAGE analysis showed that the edestin (consisting of acidic and basic subunits, AS and BS) was the main protein component for HPI and HPI-11S, while HPI-7S was composed of the BS of edestin and a subunit of about 4.8 kDa. DSC analysis characterized thermal transition of the edestin component and the possible present form of different subunits. Except lysine and sulfur-containing amino acids, the essential amino acids of various HPIs met the suggested requirements of FAO/WHO for 2–5 year old infants. The proportion of essential amino acids to the total amino acids (E/T) for HPI (as well as HPI-11S) was significantly higher than that of SPI. In an in vitro digestion model, various protein constituents of various HPIs were much easily digested by pepsin plus trypsin, to release oligo-peptides with molecular weight less than 10.0 kDa (under reduced condition). Only after pepsin digestion, in vitro digestibility of HPIs was comparable to that of SPI, however after pepsin plus trypsin digestion, the digestibility (88–91%) was significantly higher than that (71%) of SPI (P < 0.05). These results suggest that the protein isolates from hempseed are much more nutritional in amino acid nutrition and easily digestible than SPI, and can be utilized as a good source of protein nutrition for human consumption. 相似文献
7.
Fernando Granado-Lorencio Inés López-López Carmen Herrero-Barbudo Inmaculada Blanco-Navarro Susana Cofrades Belén Pérez-Sacristán Gonzalo Delgado-Pando Francisco Jiménez-Colmenero 《Food chemistry》2010
This paper reports a study of the physicochemical characteristics of lutein-enriched frankfurter-type products with two fat levels, and the lutein in vitro bioaccessibility in these products. In general, the high-fat products possessed better emulsion stability and greater hardness and chewiness than low-fat samples. For each fat level, the addition of lutein extract in olive oil reduced emulsion stability in meat products. The presence of lutein reduced the lightness and increased the redness of samples. Lutein was highly stable upon in vitro digestion, with overall recovery of over 84% at the end of the duodenal phase and very low isomerisation. Micellarisation was high but depended on the fat content, ranging from 29–34% (for the low-fat sample) up to 73–81% of the amount initially present (for the high-fat sample). Storage (22 days at 4 °C) did not significantly affect lutein content or bioaccessibility. Our results support the suitability of meat products as lutein carriers and as a means to increase the systematic intake of lutein. 相似文献
8.
Protein fractions (albumin, globulin, prolamin and glutelin) were extracted from defatted tartary buckwheat flour. The in vitro pepsin digestibilities of the four protein fractions were different, and albumin was more susceptible to pepsin hydrolysis. The native structure of the four protein fractions may be destroyed by heat treatment, and the digestibilities were all improved significantly (P < 0.05). Adding rutin to the digestion mixture of the four fractions did not cause a decrease in pepsin digestibility, although it did cause a significant increase in certain instances (P < 0.05). Treatment with β-mercaptoethanol (2-ME) only caused a higher initial proteolysis rate and did not increase the final digestibility distinctly except for prolamin. After pepsin digestion, the remaining proteins of unhydrolyzed albumin, globulin, prolamin and glutelin (untreated) shared some similarities. They also exhibited a minor band at 20,000 Da and a broad band at 10,000–14,000 Da. 相似文献
9.
Wenwei Zhang Shijia Liu Yihua Wang Leina Zheng Feng Liu Xiaohua Han Yulong Ren Qizhang Long Zhigang Zhao Ling Jiang Jianmin Wan 《Food chemistry》2010
Protein digestibility was determined in 18 indica and japonica raw milled rices using an in vitro pH-drop method with three- or four-enzyme system. Similar protein digestibility was found between indica and japonica rices, which is in agreement with the in vivo digestibilities in human. Cooking improved protein digestibility in the four-enzyme assay, while reducing agents exhibited apparent inhibition in multienzyme digestibility of indica and japonica rices. A significant correlation was detected between protein content and the estimates of digestibility, whereas no significant correlation was found between amylose content and digestibility estimates. SDS–PAGE analysis showed a significant difference in the degradation extent of prolamin between multienzyme and pepsin digestion, which might contribute to the inconsistence between results of this study and previous findings that in vitro protein digestibility of japonica rice was higher than that of indica rice. In addition, our results supported the previous report that waxy gene product level is not a major determinant of protein digestibility in milled rice. 相似文献
10.
The in vitro digestibility and molecular and crystalline structures of rice starches (Long-grain, Arborio, Calrose, and Glutinous) differing in amylose content were investigated and the relationship between the structure and in vitro digestibility of starch was studied. Long-grain showed the highest amylose content (27.2%), whereas Glutinous showed the lowest amylose content (4.2%). Long-grain had the highest average amylopectin branch chain length (18.8) and proportion (8.7%) of long branch chains (DP ≥ 37), and the lowest proportion (26.9%) of short branch chains (DP 6–12). Among the non-waxy rice starches (Long-grain, Arborio, and Calrose), Calrose had the lowest average chain length (17.7) and the lowest proportion (7.1%) of long branch chains (DP ≥ 37). The relative crystallinity of rice starch followed the order: Glutinous (33.5%) > Calrose (31.4%) > Arborio (31.0%) > Long-grain (29.9%). Long-grain had the highest gelatinization temperature and the lowest gelatinization temperature range, whereas Glutinous showed the highest gelatinization temperature range and gelatinization enthalpy. Arborio had the highest melting enthalpy for amylose–lipid complex among the tested rice starches. Pasting temperature, setback, and final viscosity increased with increasing amylose content, whereas the peak viscosity and breakdown showed negative correlations with amylose content. The rapidly digestible starch (RDS) content of the tested rice starches followed the order: Glutinous (71.4%) > Calrose (52.2%) > Arborio (48.4%) > Long-grain (39.4%). Contrary to this, the slowly digestible starch (SDS) and resistant starch (RS) contents showed an opposite trend compared to RDS. Digestibility (RDS, SDS, and RS) of the rice starches was significantly correlated (p ≤ 0.05) with amylose content, proportions of DP 6–12 and DP 13–24, relative crystallinity, intensity ratio (of 1047 cm−1 to 1022 cm−1 from Fourier transform infrared spectroscopy), swelling factor, amylose leaching, onset temperature of gelatinization, gelatinization temperature range, gelatinization enthalpy, pasting temperature, peak viscosity, breakdown, setback, and final viscosity. 相似文献
11.
Lillian Barros Montserrat DueñasMaria Inês Dias Maria João SousaCelestino Santos-Buelga Isabel C.F.R. Ferreira 《Food chemistry》2012,132(2):841-848
Coriandrum sativum L. is a source of a variety of polyphenols and other phytochemicals, related to its high antioxidant activity and to its use for indigestion, rheumatism, and prevention of lipid peroxidation damage. Plant cell cultures are a means to study or to produce some active metabolites, such as polyphenols. This technique was applied to the investigation of coriander, and a detailed analysis of individual polyphenols in vivo and in vitro grown samples was performed. The in vivo vegetative parts showed quercetin derivatives as the main flavonoids and quercetin-3-O-rutinoside (3296 mg/kg dw) was the main polyphenol found in this part of coriander. The fruits revealed only phenolic acids and derivatives, caffeoyl N-tryptophan hexoside (45.33 mg/kg dw) being the most abundant phenolic derivative. In vitro samples also gave a high diversity of polyphenols, being C-glycosylated apigenin (2983 mg/kg dw) the main compound. Anthocyanins were only found in clone A, which was certainly related to its purple pigmentation, and peonidin-3-O-feruloylglucoside-5-O-glucoside was the major anthocyanin found (1.70 μg/kg dw). In vitro culture can be used to explore new industrial, pharmaceutical, and medicinal potentialities, such as the production of secondary metabolites like flavonoids. 相似文献
12.
Soy protein isolate (SPI) nanoparticles (28–179 nm) were prepared by employing a cold gelation method with a slight modification. The obtained nanoparticles exhibited uniform size distribution and spherical shape with a unique honeycomb-like core structure. Nanoparticle characteristics including size, surface charge and hydrophobicity could be adjustable by changing calcium concentration and environmental pH. Generally, higher calcium concentration and lower pH led to formation of nanoparticles with larger size, lower surface charge and hydrophobicity. Both protein conformation and nanoparticle dissociation studies indicated that calcium likely shielded negative charges on the SPI polypeptide chains, and functioned as a salt-bridge to permit polypeptide chains to approach one another. In this process, calcium favoured the development of β-sheet structures to form SPI aggregates stabilised by hydrogen bonding. These aggregates were then associated to build SPI nano-networks through hydrophobic interactions. In vitro study indicated that the SPI nanoparticles were non-toxic and mainly located in the cytoplasm when uptaken into Caco-2 cells. 相似文献
13.
Hung-Chih Ting Yu-Wen Hsu Chia-Fang Tsai Fung-Jou Lu Ming-Chih Chou Wen-Kang Chen 《Food chemistry》2011
The antioxidant capacity of seabuckthorn (Hippophae rhamnoides L.) seed oil was investigated with a number of established in vitro assays and in an in vivo study of carbon tetrachloride (CCl4)-induced oxidative stress in mice. The results showed that DPPH radical scavenging activity, ferrous ion chelating activity, reducing power and inhibition of lipid peroxidation activity all increased with increasing concentrations of seabuckthorn seed oil. Moreover, the EC50 values of seabuckthorn seed oil from the hydrogen peroxide, superoxide radical, hydroxyl radical scavenging assays were 2.63, 2.16 and 0.77 mg/ml, respectively. In the in vivo study, seabuckthorn seed oil inhibited the toxicity of CCl4, as seen from the significantly increased activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. The GSH content in the liver was also increased, whereas hepatic malondialdehyde was reduced. Taken together, these results clearly indicate that seabuckthorn seed oil has significant potential as a natural antioxidant agent. 相似文献
14.
Effects of baking on protein digestibility of organic spelt products determined by two in vitro digestion methods 总被引:1,自引:0,他引:1
E.-S.M. Abdel-Aal 《LWT》2008,41(7):1282-1288
Consumption of organic foods is steadily increasing because it is believed to be healthier than conventional foods. This study was designed to investigate protein digestibility of organic spelt bread, biscuit, cookie and muffin in comparison to their corresponding normal wheat products. Three types of fermented bread products namely, yeast leavened, sour and yeast/sour dough were evaluated. Protein digestibility was assessed based on two methods, three-enzyme one-step and two-enzyme two-step digestion in vitro. The one-step digestion method produced results that were comparable with in vivo (rat) methods whereas the two-step digestion method was more reliable in determining differences among the examined wheat products. Organic spelt used in the present study was comparable to common wheat in protein content averaging 15.4 g/100 g dry matter. Slight differences were observed between organic spelt and common wheat products in protein digestibility determined by the two digestion methods. However, significant differences were found among each wheat products. In general, after baking protein digestion was significantly increased. Spelt and common wheat bread products had similar protein digestibility within each type of bread with sour dough breads had the highest protein digestibility. Biscuit, cookie and muffin products possessed lower protein digestibility than breads. In general, variations in protein digestibility due to baking were more noticeable than that found between the two wheats. 相似文献
15.
The purpose of this study was to examine the impact of emulsifier type on the micro-structural changes that occur to emulsified lipids as they pass through a model gastrointestinal system. Lipid droplets initially coated by different kinds of emulsifiers (lecithin, Tween 20, whey protein isolate and sodium caseinate) were prepared using a high speed blender. The emulsified lipids were then passed through an in vitro digestion model that simulated the composition (pH, minerals, surface active components, and enzymes) of mouth, stomach and small intestine juices. The change in structure and properties of the lipid droplets were monitored by laser scanning confocal fluorescence microscopy, conventional optical microscopy, light scattering, and micro-electrophoresis. In general, there was a decrease in mean droplet diameter (d32) as the droplets moved from mouth to stomach to small intestine. The electrical charge on the droplets stabilized by lecithin, Tween 20 and sodium caseinate were negative throughout the model GI system, while those stabilized by whey protein were positive in the stomach. This suggests that at least some of this globular protein remained attached to the droplet surfaces. The data was interpreted in terms of the competitive adsorption of phospholipids/bile salts with the adsorbed emulsifiers, as well as the enzymatic digestion of proteins and lipids. These results enhance our understanding of the physicochemical and structural changes that may occur to emulsified lipids within the gastrointestinal tract, which may have important consequences for the design of functional foods that alter lipid bioavailability. Nevertheless, there were appreciable differences between the behavior of emulsions within the in vitro model used in this study and literature reports of their behavior within in vivo studies, which highlights the need for more realistic in vitro digestion models. 相似文献
16.
17.
The effects of citric acid deamidation on the physiochemical properties of wheat gluten were investigated. In vitro digestion was carried out to determine changes of molecular weight distribution, amino acids composition and antioxidant efficacy of wheat gluten hydrolysates. Results indicated that citric acid deamidation significantly increased gluten solubility and surface hydrophobicity, at a neutral pH. Deamidation induced molecular weight distribution change of gluten with little proteolysis. Results from FTIR indicated that the α-helix and β-turn of deamidated gluten increased accompanied by a decrease of the β-sheet structure. After deamidation, in vitro pepsin digestibility of wheat gluten decreased, while in vitro pancreatin digestibility increased. The oxygen radical absorbance capacity (ORAC) activity of the in vitro digests decreased with increase of deamidation time. The high Lys and total essential AAs amounts in the final digests suggested that the nutritional values of wheat gluten after deamidation might be enhanced. 相似文献
18.
Structural characteristics of peptides extracted from Cantonese sausage during drying and their antioxidant activities 总被引:2,自引:0,他引:2
Weizheng Sun Haifeng Zhao Qiangzhong Zhao Mouming Zhao Bao Yang Na Wu Yiling Qian 《Innovative Food Science and Emerging Technologies》2009,10(4):558-563
Two peptide fractions (P1 and P2) were isolated from Cantonese sausages at different drying periods by ultrafiltration. P1 possessed a stronger 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in the first 18 h of drying and a weaker activity during the rest period, comparing with P2. The analysis of amino acid composition indicated that histidine was the major amino acid in both peptide fractions, which content was changed during the process. In addition, Glu, Gly, Arg were important constituent amino acids in both peptide fractions. A significant (P < 0.05) decrease of >10 kDa peptide fraction and increases of 2–3 and <2 kDa peptide fractions were detected when comparing with peptides at 0 h. However, no significant difference was found for all the peptide fractions at different drying periods, except for 2–3 kDa peptides. A significant (P < 0.05) correlationship was found between lipid oxidation and antioxidant activities.
Industrial relevance
Cantonese sausage has gained much popularity and acceptance in China and many other countries. In this work, two peptide fractions were isolated from Cantonese sausage. A good antioxidant activity was observed for each peptide fraction. Endogenous peptides resulting from proteolysis offer a promising approach to improve lipid stability for meat industry. It is helpful to retard lipid oxidation in order to improve its quality. 相似文献19.
Changes in lipid composition,fatty acid profile and lipid oxidative stability during Cantonese sausage processing 总被引:3,自引:0,他引:3
Lipid composition, fatty acid profile and lipid oxidative stability were evaluated during Cantonese sausage processing. Free fatty acids increased with concomitant decrease of phospholipids. Total content of free fatty acids at 72 h in muscle and adipose tissue was 7.341 mg/g and 3.067 mg/g, respectively. Total amount of saturated, monounsaturated and polyunsaturated fatty acids (SFA, MUFA, and PUFA) in neutral lipid exhibited a little change during processing, while the proportion of PUFA significantly decreased in the PL fraction. The main triacylglycerols were POO + SLO + OOO, PSO (P = palmitic acid, O = oleic acid, L = linoleic acid, S = stearic acid), and a preferential hydrolysis of palmitic, oleic and linoleic acid was observed. Phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were the main components of phospholipids and PE exhibited the most significant degradation during processing. Thiobarbituric acid values (TBARS) increased while peroxide values and hexanal contents varied during processing. 相似文献
20.
Okara, a byproduct of soymilk production, has been upgraded through the use of an enzymatic treatment with Ultraflo L® to give a product (okaraET) which has a higher content of soluble dietary fibre and an enhanced ratio of soluble: insoluble fibre than is found in okara without treatment. Polysaccharides were isolated from okaraET by sequential extraction to yield soluble fractions in water (22%), CDTA (8.7%), alkali (37.7%) without and NaClO2 (9.1%) and the cellulosic residue represents a (22.5%). The physicochemical properties of okaraET were improved due to the enzymatic treatment: oil retention capacity (6.94 g/g), water retention capacity (10.76 g/g) and swelling capacity (13.85 g/g) were higher than in okara that had not undergone enzymatic treatment. The gelation capacity (8%) and the cation exchange capacity (8.96 mEq/kg) of okaraET were lower than that of other byproducts. Short chain fatty acid production during in vitro fermentation of okaraET by a pure culture of Bifidobacterium bifidus was mainly represented by acetic acid, followed by propionic and butyric acids. In addition, the decreases in pH and substrate consumption demonstrated the bifidogenic capacity of okaraET. 相似文献