Characterization and Antioxidant Activity of Products Derived from Xylose–Bovine Casein Hydrolysate Maillard Reaction: Impact of Reaction Time

The characterization and antioxidant activity on Maillard reaction products (MRPs) derived from xylose and bovine casein hydrolysate (BCH) was investigated at 100 °C and initial pH 8.0 as a function of reaction time. The pH values and free amino groups contents of xylose–BCH MRPs remarkably decreased with the reaction time up to 8 h, whereas their browning intensities significantly increased (p < 0.05). After 4 h of heat treatment, the fluorescence properties of xylose–BCH MRPs reached the maximum. There was a production of higher and smaller molecular substances in xylose–BCH MRPs with an increased reaction time, as analyzed by size exclusion chromatography. The 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging capacity and ferrous reducing activity of xylose-BCH MRPs gradually increased with the reaction time extended from 0 to 8 h

Surface Hydrophobicity and Functional Properties of Citric Acid Cross-Linked Whey Protein Isolate: The Impact of pH and Concentration of Citric Acid

The effects of citric acid-mediated cross-linking under non-acidic conditions on the surface hydrophobicity, solubility, emulsifying, and foaming properties of whey protein isolate (WPI) were investigated. In this research, citric acid-mediated cross-linking could not only increase the surface hydrophobicity of whey proteins at pH 7.0 and 8.0, but it also improved its emulsifying and foaming properties. The emulsifying activity and foaming ability of WPI reached a maximum under the condition of 1% citric acid and pH 7.0. However, the solubility of WPI-CA gradually decreased with pH and the content of citric acid increased. Therefore, the cross-linking mediated by citric acid under non-acidic aqueous conditions, markedly altered the surface hydrophobicity and enhanced emulsifying and foaming properties of WPI

Effects of Soybean Oil Body as a Milk Fat Substitute on Ice Cream: Physicochemical, Sensory and Digestive Properties

Soybean oil body (SOB) has potential as a milk fat substitute due to its ideal emulsification, stability and potential biological activity. In this study, SOB was used as a milk fat substitute to prepare ice cream, expecting to reduce the content of saturated fatty acid and improve the quality defects of ice cream products caused by the poor stability of milk fat at low temperatures. This study investigated the effect of SOB as a milk fat substitute (the substitution amount was 10–50%) on ice cream through apparent viscosity, particle size, overrun, melting, texture, sensory and digestive properties. The results show SOB substitution for milk fat significantly increased the apparent viscosity and droplet uniformity and decreased the particle size of the ice cream mixes, indicating that there were lots of intermolecular interactions to improve ice cream stability. In addition, ice cream with 30% to 50% SOB substitution had better melting properties and texture characteristics. The ice cream with 40% SOB substitution had the highest overall acceptability. Furthermore, SOB substitution for milk fat increased unsaturated fatty acid content in ice cream and fatty acid release during digestion, which had potential health benefits for consumers. Therefore, SOB as a milk fat substitute may be an effective way to improve the nutritional value and quality characteristics of dairy products

Soybean-Oil-Body-Substituted Low-Fat Ice Cream with Different Homogenization Pressure, Pasteurization Condition, and Process Sequence: Physicochemical Properties, Texture, and Storage Stability

The purpose of this research was to explore the impacts of different homogenization pressures, pasteurization conditions, and process sequence on the physical and chemical properties of soybean oil body (SOB)-substituted low-fat ice cream as well as the storage stability of SOB-substituted ice cream under these process parameters. With the increase of homogenization pressure (10–30 MPa), the increase of pasteurization temperature (65 °C for 30 min–85 °C for 15 min), and the addition of SOB before homogenization, the overrun and apparent viscosity of ice cream increased significantly, and the particle size, hardness, and melting rate decreased significantly. Thus, frozen dairy products of desired quality and condition could be obtained by optimizing process parameters. In addition, the SOB ice cream showed better storage stability, which was reflected in lower melting rate and hardness and more stable microstructure compared with the full-milk-fat ice cream. This study opened up new ideas for the application of SOB and the development of nutritious and healthy ice cream. Meanwhile, this research supplied a conceptual basis for the processing and quality optimization of SOB ice cream

Heat-induced Maillard reaction of the tripeptide IPP and ribose: Structural characterization and implication on bioactivity

peer-reviewedMaillard reaction products (MRPs) were prepared from aqueous model mixtures containing 60 g L− 1 ribose and 30 g L− 1 of the bioactive tripeptide IPP (Ile-Pro-Pro), heated at 98 °C. MRP and associated reactions with changes in IPP were observed within one hour of heat-treatment. The pH of MRPs decreased significantly during the heat treatment of IPP–ribose mixtures from 9.0 to 7.6 after one hour. The amino group content, IPP and ribose concentration decreased significantly during heat treatment. The fluorescence intensity of the IPP–ribose MRPs reached the maximum within 2 h. Modification of the UV/vis spectra for IPP–ribose MRPs was mainly due to a condensation reaction of IPP with ribose. Compounds with molecular weight between 300 and 650 Da were dominant while compounds smaller than 250 Da were also produced during the reactions, as characterized by size exclusion chromatography. Mass spectrometry revealed that IPP was conjugated to ribose at the N-terminal (m/z of 458.3) upon heat-treatment. The presence of ribose also promoted peptide degradation to dehydrated IP (m/z of 211.1). IPP–ribose MRPs lost the known angiotensin-I-converting enzyme (ACE) inhibitory activity of IPP; however, strong antioxidant properties were detected

Structure and antioxidant activity of Maillard reaction products from α-lactalbumin and β-lactoglobulin with ribose in an aqueous model system

peer-reviewedMaillard reaction products (MRPs) were prepared from aqueous model mixtures containing 3% (w/w) ribose and 3% (w/w) of the dairy proteins α-lactalbumin (α-LA) or β-lactoglobulin (β-LG), heated at 95 °C, for up to 5 h. The pH of MRPs decreased significantly during heat treatment of α-LA-Ribose and β-LG-Ribose mixtures from 8.4 to 5.3. The amino group content in MRPs, derived from the α-LA-Ribose and β-LG-Ribose model system, was decreased noticeably during the first hour and did not change thereafter. The loss of free ribose in MRPs was higher for β-LG-Ribose than for α-LA-Ribose. During the Maillard reaction, the concentration of native and non-native α-LA, or β-LG, decreased and the formation of aggregates was observed. Fluorescence intensity of the β-LG-Ribose MRPs reached maximum within 1 h, compared to 2 h for α-LA-Ribose MRPs. Meanwhile, modification of the UV/vis absorption spectra for α-LA and β-LG was mainly due to a condensation reaction with ribose. Dynamic light scattering showed a significant increase in the particle size of the MRPs. Size exclusion chromatography of MRPs revealed the production of both high and low molecular weight material. Electrophoresis of MRPs indicated polymerization of α-LA and β-LG monomers via inter-molecular disulfide bridge, but also via other covelant bonds. MRPs from α-LA-Ribose and β-LG-Ribose exhibited increased antioxidant activities, therefore theses MRPs may be used as natural antioxidants in food products.Innovative Research Team of Higher Education of Heilongjiang ProvinceProgram for New Century Excellent Talents in Heilongjiang Province Universit

Reproducibility and Validity of a Semi-Quantitative Food Frequency Questionnaire for Assessing Dietary Intake of Vegetarians and Omnivores in Harbin, China

This study aims to evaluate the reproducibility and validity of a semi-quantitative food frequency questionnaire (SQFFQ) developed for vegetarians and omnivores in Harbin, China. Participants (36 vegetarians and 64 omnivores) administered SQFFQ at baseline (SQFFQ1) and six months later (SQFFQ2) to assess the reproducibility. The 24 h recalls (24 HRs) for three consecutive days were completed between the administrations of two SQFFQs to determine the validity. For reproducibility, Pearson correlation coefficients between SQFFQ1 and SQFFQ2 for vegetarians and omnivores were 0.45~0.88 and 0.44~0.84, respectively. For validity, unadjusted Pearson correlation coefficients were 0.46~0.83 with an average of 0.63 and 0.43~0.86 with an average of 0.61, respectively; energy-adjusted Pearson correlation coefficients were 0.43~0.82 with an average of 0.61 and 0.40~0.85 with an average of 0.59, respectively. Majority of the correlation coefficients for food groups and macronutrients decreased or remained unchanged after energy adjustment. Furthermore, all correlations were statistically significant (p < 0.05). Bland–Altman plots also showed reasonably acceptable agreement between the two methods. In conclusion, the SQFFQ developed in this study has reasonably acceptable reproducibility and validity

Incorporation of Blue Honeysuckle Juice into Fermented Goat Milk: Physicochemical, Sensory and Antioxidant Characteristics and In Vitro Gastrointestinal Digestion

The addition of fruit juice may improve the physicochemical and functional characteristics of dairy products. The study evaluated the effect of 1–6% (v/v) blue honeysuckle juice (BHJ) on the physicochemical, sensory and antioxidant characteristics of fermented goat milk (FGM) during 21 days of refrigerated storage and in vitro gastrointestinal digestion. The incorporation of BHJ significantly increased (p a*) value, total phenolic content (TPC) and ferric ion-reducing antioxidant power during storage. Additionally, BHJ affected the microstructure and sensory score of the samples. FGM treated with 4% (v/v) BHJ exhibited the highest overall acceptability. The supplementation of BHJ diminished the goaty flavor and promoted in vitro protein digestion. Furthermore, the TPC was enhanced in addition to the antioxidant activity of FGM containing BHJ throughout the in vitro digestion. Therefore, FGM supplemented with BHJ serves as a novel and attractive goat dairy product

Synthesis, characterization and in vitro biological evaluation of two matrine derivatives

Abstract Matrine is a traditional Chinese medicine and botanical pesticide with broad biological activities, including pharmacological and agricultural activities. In present work, two matrine derivatives have been successfully synthesized via introducing indole and cyclohexylamino to 13 position of matrine, respectively, with sophocarpine as starting material, and structurally characterized via infrared spectroscopy(IR), MS, 1 H NMR, 13 C NMR and X-ray crystal diffraction. The results of the in vitro biological activity tests showed that these two matrine derivatives exhibited even better activities against human cancer cells Hela229 and insect cell line Sf9 from Spodoptera frugiperda (J. E. Smith) than that of parent matrine, suggesting that the heterocyclic or cyclic group can dramatically increase the biological activity of matrine. It is worth to mention that 13-indole-matrine could possibly inhibit the growth of insect cells or human cancer cells by inducing cell apoptosis. The results of the present study provide useful information for further structural modifications of these compounds and for exploring new, potent anti-cancer agents and environment friendly pesticides