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Incorporating high level of potato flour into wheat flour enhances nutritional values of bread but induces a series of problems that lead to the decline of the bread quality. To overcome the barrier, wheat gluten and carboxymethylcellulose (CMC) were added into potato–wheat composite flour to improve dough machinability and bread quality. The rheological properties, thermo-mechanical properties and microstructures of dough were investigated. The results showed that the interaction between gluten and CMC mitigated the discontinuity of gluten matrix and gluten protein aggregation caused by the addition of potato flour, which yielded a more branched and compact gluten network. The compact three-dimensional viscoelastic structure induced improvements of gas retention capacity and dough stability, making it mimic the machinability properties of wheat flour dough. Bread qualities were apparently improved with the combined use of 4% gluten and 6% CMC, of which specific volume increased by 42.86%, and simultaneously, hardness reduced by 75.93%.  相似文献   

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Ablo is a rice-based bread consumed in Southern Benin. We investigated the impact of pre-cooking conditions and starch characteristics on dough and Ablo physical properties. The solid-like behaviour of doughs measured by rheological sweep tests appears significantly negatively correlated to Ablo quality; above a starch gelatinisation level (7%–8%), the solid-like behaviour of the doughs increased sharply and the fluidity decreased, leading to Ablo of poor quality. A comparison between three rice cultivars tends to show that rice with low amylose content and/or gelatinisation temperature gives dough with higher fluidity and Ablo with lower density. In addition, a specific rheological test for measuring simultaneously dough expansion and rheological properties during heating has been developed. It shows that whatever the rice variety, thermal expansion of proofed dough begins and is followed by a dough/crumb transition. This innovative rheological test could be used for studying dough/crumb transition for other types of breads.  相似文献   

5.
In the present study, storage proteins from five different wheat cultivars were extracted, fractionated and evaluated for their accumulation at different stages of development. SDS–PAGE analysis revealed that the accumulation of high molecular weight glutenin subunits was cultivar and stage dependent. However, low molecular weight glutenin subunits’ accumulation was not altered significantly after 16 days post anthesis in any of the cultivars. The rheological parameters (storage- and loss-modulus) of dough and gluten showed close association with either gliadins or glutenins. Peptidyl prolyl cis–trans isomerase (PPIase) activity, measured at different stages of grains development, showed variability with both the developmental stage and cultivar, and appeared to be primarily due to cyclophilins. Principal component analysis revealed the association of PPIase activity with either gliadin or total proteins, suggesting their significant role in the deposition of storage proteins in wheat.  相似文献   

6.
For quality control of Chinese materia medica (CMM), an attempt on fingerprint–efficacy study of artificial Calculus bovis was developed in this work. Chemical fingerprints of artificial C. bovis samples from ten different sources were determined by UPLC–ELSD and investigated by similarity analysis and hierarchical clustering analysis. Antibacterial effects of these samples on Escherichia coli growth were measured using microcalorimetry. The fingerprint–efficacy relationship of chemical fingerprint and antibacterial effect of artificial C. bovis were established by multi-linear regression analysis. Our results showed that the sources and places of production of artificial C. bovis had some important influence on the chemical fingerprints and antibacterial effects of this CMM. These artificial C. bovis could be grouped into four clusters according to their chemical fingerprints and antibacterial effects. Compounds cholic acid, taurocholate sodium, hyodeoxycholic acid and one unknown compound might be the major effective components for quality control of this CMM. Fingerprint–efficacy study provided a powerful way and some insight for the quality control of artificial C. bovis and other CCMs.  相似文献   

7.
An HPLC–ELSD method was first developed for the quantitative analysis of principle triterpenoids in Ilex hainanensis, Ilex stewardii and Ilex pubescens. The established method, with excellent precision, repeatability and recovery, was successfully applied to determine four triterpenoids in 24 samples from different species and medicinal parts of Ilex, and the changing trend was discussed. HPLC–ESI–MSn was used for the identification of constituents in samples. The proposed method was simple, effective and suitable for investigations of these plants. Furthermore, the ethanol extracts from leaves of Ilex species, as well as their main components, were assessed for their antibacterial activities. The results indicated that the extracts of I. hainanensis, I. stewardii and I. pubescens could inhibit the growth of the tested oral pathogens, Streptococcus mutans and Actinomyces viscosu. Particularly, ilexgenin A was the most effective with MIC values of 7.8 and ?3.9 μg/ml, respectively.  相似文献   

8.
The objective of this study was to investigate the effects of bovine GH1, CAPN1 and CAST gene polymorphisms on carcass and meat traits in Nellore and Nellore x Bos taurus beef cattle. Three hundred animals were genotyped for GH1/MspI (TC/G in intron 3), CAPN316 (AF_252504.2:g.5709C > G) and CAST/RsaI (AY_008267.1:g282C > G) and phenotyped for rib eye area, backfat thickness, intramuscular fat, shear force (SF), and myofibrillar fragmentation index (MFI). No significant associations were observed between the GH1/MspI and CAST/RsaI polymorphisms and phenotypes, although the relation between the CAST/RsaI genotypes and meat tenderness evaluated by MFI approached significant. The fact that the CAPN316 polymorphism did not show adequate segregation in Nellore cattle confirms the difficulty of using this marker in breeding programs of different Bos indicus breeds. However, the positive results of the association analysis obtained for Nellore x B. taurus crosses contributed to the validation of previous findings.  相似文献   

9.
The glucosinolate and phenolic profiles of 37 rocket salad accessions (32 Eruca sativa and 5 Diplotaxis tenuifolia) were obtained by liquid chromatography–mass spectrometry. Eleven desulpho-glucosinolates (DS-GLSs) were isolated and the glucosinolate profiles did not differ between the two species. Total DS-GLS content, expressed as sinigrin equivalents (SE) revealed a certain variability, ranging from 0.76 to 2.46 g kg−1 d.w. but, again, the quantitative analysis did not discriminates Eruca from Diplotaxis. The polyphenol evaluation by HPLC-DAD–MS allowed the identification of two different classes of compounds in the two rocket salad species. Qualitative differences were observed between the polyphenol profiles at specific level: quercetin derivatives were the main phenolics of Diplotaxis, whereas kaempferol derivatives characterised Eruca samples. The contents of total flavonoids determined as rutin equivalents (RE) ranged from 4.68 to 31.39 g kg−1 d.w. Kaempferol-3,4′-diglucoside (71.4–82.2%) and isorhamnetin-3,4′-di-glucoside (7.8–18.4%) were always isolated as first and second more abundant phenolic compounds in Eruca samples. No marker phenolic compounds were isolated in Diplotaxis samples.  相似文献   

10.
The characteristic aromatic composition of white truffles (Tuber magnatum Pico) determines its culinary and commercial value. However modifications of truffle organoleptic proprieties occur during preservation. A study of headspace of white truffles by using Electronic nose (E-nose), gas chromatography–mass spectrometry (GC–MS) and sensory analyses was performed. Truffles were stored at different conditions for 7 days: +4 and +8 °C wrapped in blotting paper or covered by rice or none of the above. Headspace E-nose measurements and sensory analyses were performed each day. Statistical multivariate analysis of the data showed the capability of E-nose to predict sensorial analysis scores and to monitor aroma profile changes during storage. Truffle’s volatile molecules were also extracted by headspace solid phase microextraction technique and separated and identified by GC–MS. Partial Components Analysis of data was performed. E-nose and GC–MS results were in agreement and showed that truffle storage in paper at +8 °C seemed to be the best storage condition.  相似文献   

11.
A simplex-centroid experimental design was used for the optimization of both reducing and oxidizing improvers, namely Aspergillus oryzae S2 α-amylase (Amy), ascorbic acid (Asc), and glucose oxidase (GOD). This optimization was performed to enhance the dough and breadmaking qualities of soft French wheat flour and a composite counterpart that contained 30% Ukrainian wheat flour. Statistically significant correlations were calculated between the W index and textural parameters (e.g., dough chewiness and bread cohesiveness). The findings revealed that while the best mixture for French flour comprised 21.8% of Amy, 41.2% of Asc, and 37% of GOD, for the composite counterpart, it comprised 2.3% of Amy, 66% of Asc, and 31.7% of GOD. These optimized mixtures rearranged soft French wheat flour and its composite counterpart to a good quality and an improved flour texture, respectively. Additionally, they increased the loaf specific volumes of the breads made from soft French wheat flour and its counterpart by 25.8 and 45.43%, respectively, significantly decreased the breads’ susceptibility to microbial contamination, and reclassified the breads as “good” in terms of sensory attributes.  相似文献   

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The physical properties of a composite film prepared from barley bran protein and gelatin (BBG) were investigated. Tensile strength (TS) and elongation at break (E) values of the BBG film decreased as barley bran protein content increased. TS increased with increasing gelatin content, but E values decreased. The optimal conditions for the preparation of the BBG film were 3 g barley bran protein, 3 g gelatin, and 1 g sorbitol in 100 mL film-forming solution. In order to inhibit the growth of pathogenic bacteria, a BBG film containing grapefruit seed extract (GSE) was prepared. After 15 days of storage, populations of Escherichia coli O157:H7 and Listeria monocytogenes inoculated on salmon packaged with the BBG film containing GSE decreased by 0.53 and 0.50 log CFU/g, respectively, compared to the control. Also, packing salmon with the BBG film containing GSE decreased the peroxide value and thiobarbituric acid value by 23.0% and 23.4%, respectively.  相似文献   

14.
We investigated the effect of homogentisate 1, 2 dioxygenase (HGD) gene on meat quality and carcass traits in 287 Chinese red cattle. The PCR–SSCP method was used to identify polymorphism of the HGD gene in the exon 1 and intron 1. Two polymorphisms were detected in intron 1 and two restriction sites for endonuclease HGD-BstXI and HGD-HaeIII have also been found. The HGD-BstXI genotypes showed significant effects on cooking loss, drip loss, net meat weight, carcass weight, and eye muscle area (P < 0.05). The HGD-HaeIII genotypes significant affected cooking loss, muscle fibre diameter, shear force, drip loss, and carcass yield ratio (P < 0.05). Moreover, we found significant effects of diplotypes on cooking loss, muscle fibre diameter, shear force, drip loss, net meat weight, carcass weight, and eye muscle area (P < 0.05).  相似文献   

15.
High hydrostatic pressure (HHP) is an effective nonthermal food processing method for microbial inactivation with minimal change to sensory and nutritional values. However, the resistance of endospores to high pressure hinders application of HHP to freshly squeezed vegetable juice, especially from leafy vegetables that are susceptible to contamination of soil bacteria, such as endospore-forming Bacillus cereus. A combination of TiO2–UV photocatalysis and HHP was used in the processing of freshly squeezed Angelica keiskei juice, and inactivation of naturally occurring microbes, especially B. cereus, was investigated. Yeasts and molds, coliform bacteria, and Pseudomonas were inactivated by HHP to levels below the detection limit, but B. cereus survived HHP and grew during 8 days of subsequent refrigerated storage (4 °C). However, no colonies of yeasts and molds, coliform bacteria, Pseudomonas, or B. cereus were detected in A. keiskei juice after processing with a combination of TiO2–UV photocatalysis and HHP. Although B. cereus in juice processed with the combination treatment recovered and grew to 2.02 log CFU/mL on day 6 of storage, this level was less than the population of B. cereus in unprocessed Angelica keiskei juice immediately after squeezing.  相似文献   

16.
In this study, encapsulating fish oil, as a source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), with multi-layered interfacial membranes using electrostatic attraction between sodium caseinate and gum arabic and its usage in the enrichment of fruit juice was investigated. Initially, optimum conditions for forming a stable complex between sodium caseinate and gum arabic were determined at pH 4 and at a concentration of 0.1 g/100 ml sodium caseinate-0.2 g/100 ml gum arabic. This complex was utilized for nanoencapsulation of fish oil. Encapsulation efficiency and particle size were obtained as 78.88 ± 2.89%, 232.3 nm, respectively. Fish oil nanocomplex containing 40–50–60 mg EPA + DHA were used in the enrichment of 100 ml fruit juice. After in vitro digestion, the bioaccessibility of EPA, DHA and EPA + DHA were found as 56.16 ± 6.39, 36.25 ± 5.38 and 47.37 ± 10.65 percent, respectively (p < 0.05). This study indicates that stable protein–polysaccharide complexes can be used for nanoencapsulating hydrophobic compounds such EPA and DHA, useful for enrichment of non- or low-fat beverages.  相似文献   

17.
Berries and red fruits are rich dietary sources of polyphenols with reported health benefits. More than 50 different flavonols (glycosides of quercetin, myricetin, kaempferol, isorhamnetin, syringetin and laricitrin) have been detected and quantified with HPLC–MSn in fruits of blueberry, bilberry, cranberry, lingonberry, eastern shadbush, Japanese wineberry, black mulberry, chokeberry, red, black and white currants, jostaberry, red and white gooseberry, hardy kiwifruit, goji berry, rowan, dog rose, Chinese and midland hawthorn, wild and cultivated species of blackberry, raspberry, strawberry and elderberry. The phenolic constituents and contents varied considerably among the analyzed berry species. Elderberry contained the highest amount of total flavonols (450–568 mg kg−1 FW), followed by berry species, containing more than 200 mg kg−1 FW of total: chokeberry (267 mg kg−1), eastern shadbush (261 mg kg−1), wild grown blackberry (260 mg kg−1), rowanberry (232 mg kg−1), american cranberry (213 mg kg−1) and blackcurrants (204 mg kg−1). Strawberry (10.5 mg kg−1) and white currants (4.5 mg kg−1) contained the lowest amount of total flavonols. Quercetins represent the highest percentage (46–100%) among flavonols in most analyzed berries. In wild strawberry and gooseberry the prevailing flavonols belong to the group of isorhamnetins (50–62%) and kaempferols, which represent the major part of flavonols in currants (49–66%). Myricetin glycosides could only be detected in chokeberry, rowanberry and species from the Grossulariaceae, and Adoxaceae family and Vaccinium genus. Wild strawberry and blackberry contained from 3- to 5-fold higher total flavonols than the cultivated one.  相似文献   

18.
An LC–MS/MS method for analyzing seven folates in food was developed and validated. 5-Methyltetrahydrofolate, 5-formyltetrahydrofolate, 10-formylfolic acid, tetrahydrofolate and folic acid were quantified using a stable isotope dilution assay (SIDA) with deuterated analogues as internal standards. Additionally, 10-formyldihydrofolate and 5,10-methenyltetrahydrofolate were quantified using deuterated internal standards different in structure. Due to interconversion of 5,10-methenyltetrahydrofolate to 5-formyltetrahydrofolate and 10-formyldihydrofolate to 10-formylfolic acid during sample preparation, a SIDA was not considered because of a resulting double calculation of the amounts interconverting. [2H4]-5-methyltetrahydrofolate was used as internal standard for 5,10-methenyltetrahydrofolate, due to a similar retention time, and [2H4]-10-formylfolic acid as well as [2H4]-5-methyltetrahydrofolate was used for 10-formyldihydrofolate, because no internal standards co-elute. To confirm that no matrix effects affect the quantitation of 5,10-methenyltetrahydrofolate and 10-formyldihydrofolate, postcolumn infusion experiments were performed. Validation of the assay was accomplished by determining linearity, precision, recovery, limit of detection and limit of quantitation. The latter parameters were partly obtained by application of a dual-isotope label design including [13C5]-labeled folates. The amounts of 5,10-methenyltetrahydrofolate in the purified extracts of different food samples ranged between 0.3 and 1.3 % and for 10-HCO-H2folate between 0.05 and 8 % of the total folate amount. Correction for incomplete recovery of the latter folate during cleanup indicates even higher contents. Therefore, especially 10-formyldihydrofolate should not be neglected to obtain accurate results for folates.  相似文献   

19.
Curcuma xanthorrhiza and Zingiber zerumbet are two of the most commonly used ingredients in Indo-Malaysian traditional medicines, health supplements and tonics. Recently, a number of products derived from the aqueous extracts of these species have appeared in the market in the form of spray-dried powder packed in sachet or bottle. On-line high performance liquid chromatography, coupled with diode array detection and electrospray ion trap tandem mass spectroscopy (HPLC–DAD–ESI–MSn), was used to analyze the components in the antioxidant-active fractions from the rhizomes of these species. Three components were identified from C. xanthorrhiza, including bisdemethoxycurcumin (1), demethoxycurcumin (2) and curcumin (3). The active fraction from Z. zerumbet consisted of five components, including kaempferol 3-O-rhamnoside (4), compound 5 [kaempferol 3-O-(2″-O-acetyl)rhamnoside (5a) or kaempferol 3-O-(3″-O-acetyl)rhamnoside (5b)], kaempferol 3-O-(4″-O-acetyl)rhamnoside (6), kaempferol 3-O-(3″,4″-O-diacetyl)rhamnoside (7) and kaempferol 3-O-(2″,4″-O-diacetyl)rhamnoside (8). To confirm their identities, the components from Z. zerumbet were isolated conventionally and were analyzed by spectroscopic techniques as well as by comparison with literature data.  相似文献   

20.
Several smoking conditions were examined with the objective of enhancing the numbers of lactic acid bacteria (LAB) by natural means in vacuum-packaged cold-smoked salmon during 21 days of storage at 5 degrees C. Three combinations of salting, drying, and smoking were used: (i) dry salting x time of salting (2 or 6 h); (ii) wet salting (6 h) x dry salting (6 h) x with or without sugar; and (iii) wet salting (6 h) x dry salting (6 h) x different times of smoking (2 or 6 h of drying and 2 or 6 h of smoking). Two batches were processed for each set of conditions. Determinations of pH and salt content in the water phase were carried out for products in each treatment. Microbiological analyses (total viable count, total LAB, Lactobacillus spp., and Enterobacteriaceae) also were conducted at the beginning of storage (t0) and after 21 days of refrigerated storage (tl). There were differential increases in total LAB and lactobacilli during the storage period according to the treatment performed. The most effective treatment to enhance LAB growth was 6 h of dry salting with sugar, 6 h of drying, and 2 h of smoking. These salting-drying-smoking conditions also selected the LAB as the dominant flora at the end of the storage period. The LAB promoted by these processing parameters seem to be potentially useful protective cultures because of their anti-Listeria activity. From the results of this research, we conclude that it is possible to enhance the growth of LAB in general and that of inhibitory strains in particular by suitable choices of processing parameters.  相似文献   

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