Effect of addition of gelatin on the rheological and microstructural properties of acid milk protein gels

To gain an understanding of the gelation mechanism of mixtures of milk proteins and gelatin, rheological and microstructural properties of the mixtures were characterized following four stages. During the acidification stage (at 45\ua0°C), the presence of gelatin at sufficient concentration (higher than 1%) led to a lower storage modulus (G′) than that of the pure milk protein gels and a more heterogenous microstructure with larger milk protein clusters was formed. During the cooling (from 45 to 10\ua0°C) and annealing stage s (at 10\ua0°C), the G′ of the gels increased because of both milk gel enhancement and gelatin gelation. Higher concentrations of gelatin led to earlier formation of strand-like structures, seen in the micrographs. The gelation of gelatin changed the microstructure of whey protein isolate (WPI) gel dramatically, while gels of milk protein concentrate (MPC) and skim milk powder (SMP) maintained the typical milk gel network and gelatin formed strands and films without destroying the existing gels. During the heating stage (from 10 to 45\ua0°C), gelatin strands were melted and the G′ of the mixed gels tended to revert to the value at the end of the acidification stage, indicating that the changes caused by gelatin in the microstructure of milk protein gels after acidification are reversible. Additionally, gelatin enhanced the water holding capacity (WHC) of the gels (no serum expulsion was observed for gels containing ≥1% gelatin), without increasing gel firmness significantly

Protein concentration and hydrocolloid effect on the rheological and tribological behaviour of resulting protein solution

In recent years, the consumption of high protein beverages has increased due to the consciousness among consumers about their body weight. This study investigated the rheological, tribological and visual properties of pure proteins solutions with variable protein concentrations and with/without hydrocolloids (gelatin, κ-carrageenan, low methoxy pectin and curdlan). Although whey protein addition did not have any obvious influence on the appearances of protein solutions, it increased the stability against agglomeration and improved viscosity and lubrication property (measured as a friction coefficient) to some extent. The protein solutions became less stable with addition of the hydrocolloids under investigation, however the flow and lubrication behaviour of the protein solutions improved as the amount of hydrocolloids increased. The protein solution containing 0.25 g/100 g of curdlan showed the best lubrication property at both 15 and 37 °C

Development of rheological and sensory properties of combinations of milk proteins and gelling polysaccharides as potential gelatin replacements in the manufacture of stirred acid milk gels and yogurt

Combinations of gelling polysaccharides (xanthan/locust bean gum [X/L], carrageenan and starch) and milk proteins (whey protein isolate [WPI], sodium caseinate and skim milk powder) were evaluated as potential gelatin replacers in acid milk gels. Gels with added X/L alone showed rheological (gelling and melting) and microstructural (typical casein network with thin strand-like structures) properties similar to those of gels with gelatin. Similar to the effect of adding gelatin, milk protein fortification enhanced water holding capacity (WHC) of the gels, with WPI being the most effective. Gels with combinations of polysaccharides (except carrageenan) and WPI were stronger and had higher WHC than gels with no stabilizer. In yogurt, the combination of WPI and X/L (WPI-X/L) produced similar effects on consistency, pseudoplasticity and apparent viscosity as gelatin and higher sensory scores for thickness and stickiness than gelatin; a lower score for smoothness was observed with WPI-X/L than with gelatin

PTIGS-IdIt, a system for species identification by DNA sequences of the psbA-trnH intergenic spacer region

Abstract Background DNA barcoding technology, which uses a short piece of DNA sequence to identify species, has wide ranges of applications. Until today, a universal DNA barcode marker for plants remains elusive. The rbcL and matK regions have been proposed as the “core barcode” for plants and the ITS2 and psbA-trnH intergenic spacer (PTIGS) regions were later added as supplemental barcodes. The use of PTIGS region as a supplemental barcode has been limited by the lack of computational tools that can handle significant insertions and deletions in the PTIGS sequences. Here, we compared the most commonly used alignment-based and alignment-free methods and developed a web server to allow the biologists to carry out PTIGS-based DNA barcoding analyses. Results First, we compared several alignment-based methods such as BLAST and those calculating P distance and Edit distance, alignment-free methods Di-Nucleotide Frequency Profile (DNFP) and their combinations. We found that the DNFP and Edit-distance methods increased the identification success rate to ~80%, 20% higher than the most commonly used BLAST method. Second, the combined methods showed overall better success rate and performance. Last, we have developed a web server that allows (1) retrieving various sub-regions and the consensus sequences of PTIGS, (2) annotating novel PTIGS sequences, (3) determining species identity by PTIGS sequences using eight methods, and (4) examining identification efficiency and performance of the eight methods for various taxonomy groups. Conclusions The Edit distance and the DNFP methods have the highest discrimination powers. Hybrid methods can be used to achieve significant improvement in performance. These methods can be extended to applications using the core barcodes and the other supplemental DNA barcode ITS2. To our knowledge, the web server developed here is the only one that allows species determination based on PTIGS sequences. The web server can be accessed at http://psba-trnh-plantidit.dnsalias.org

Association Analysis of IL-17A and IL-17F Polymorphisms in Chinese Han Women with Breast Cancer

Background: Research into the etiology of breast cancer has recently focused on the role of the immunity and inflammation. The proinflammatory cytokines IL-17A and IL-17F can mediate inflammation and cancer. To evaluate the influences of IL-17A and IL-17F gene polymorphisms on the risk of sporadic breast cancer, a case-control study was conducted in Chinese Han women. Methodology and Principal Findings: We genotyped three single-nucleotide polymorphisms (SNPs) in IL-17A (rs2275913, rs3819025 and rs3748067) and five SNPs in IL-17F (rs7771511, rs9382084, rs12203582, rs1266828 and rs763780) to determine the haplotypes in 491 women with breast cancer and 502 healthy individuals. The genotypes were determined using the SNaPshot technique. The differences in the genotypic distribution between breast cancer patients and healthy controls were analyzed with the Chi-square test for trends. For rs2275913 in IL-17A, the frequency of the AA genotype was higher in patients than controls (P = 0.0016). The clinical features analysis demonstrated significant associations between IL-17 SNPs and tumor protein 53 (P53), progesterone receptor (PR), human epidermal growth factor receptor 2 (Her-2) and triple-negative (ER-/PR-/Her-2-) status. In addition, the haplotype analysis indicated that the frequency of the haplotype A rs2275913G rs3819025G rs3748067, located in the IL-17A linkage disequilibrium (LD) block, was higher in patients than in controls (P = 0.0471 after correction for multiple testing)

Recent advances on uses of protein and/or polysaccharide as fat replacers: Textural and tribological perspectives: A review

Background: The link between human health and high-calorie diets has prompted the food industry to develop low-calorie foods and fat replacers. Fat replacers are classified into protein-, polysaccharide-, and fat-based fat replacers. While the effects of protein- and polysaccharide-based fat replacers had been widely studied, combining the two molecules could create new features. Protein-polysaccharide interactions lead to the development of electrostatic complexed structures that give unique functionality and may be suitable for fat replacement. Tribology is used to understand complex mouthfeel characteristics by establishing a correlation with frictional behavior, providing valuable information in fat-related mouthfeel investigations. Scope and approach: This review highlights the electrostatic interaction between proteins and polysaccharides, and their effects on the physicochemical of reduced-fat foods are discussed based on recent approaches. Special emphasis has been given to lubrication properties. Key findings and conclusions: Protein-polysaccharide-based fat replacers could be an effective strategy for generating new products with healthier properties. They have a good ability to improve the sensory, textural, and tribological properties of reduced-fat foods. Proteins can mimic the smoothness and lubrication characteristic of fat, and polysaccharides confer some fat functions by binding large amounts of water, providing lubricity and a melting sensation; as a result, the overall sensation of the product in the mouth improves