Electrospray-Assisted Fabrication of Dextran-Whey Protein Isolation Microcapsules for the Encapsulation of Selenium-Enriched Peptide.

Selenium-enriched peptide (SP, selenopeptide) is an excellent organic selenium supplement that has attracted increasing attention due to its superior physiological effects. In this study, dextran-whey protein isolation-SP (DX-WPI-SP) microcapsules were fabricated via high-voltage electrospraying technology. The results of preparation process optimization showed that the optimized preparation process parameters were 6% DX (w/v), feeding rate Q = 1 mL/h, voltage U = 15 kV, and receiving distance H = 15 cm. When the content of WPI (w/v) was 4-8%, the average diameter of the as-prepared microcapsules was no more than 45 µm, and the loading rate for SP ranged from ~46% to ~37%. The DX-WPI-SP microcapsules displayed excellent antioxidant capacity. The thermal stability of the microencapsulated SP was improved, which was attributed to the protective effects of the wall materials for SP. The release performance was investigated to disclose the sustained-release capacity of the carrier under different pH values and an in-vitro-simulated digestion environment. The digested microcapsule solution showed negligible influence on the cellular cytotoxicity of Caco-2 cells. Overall, our work provides a facile strategy of electrospraying microcapsules for the functional encapsulation of SP and witnesses a broad prospect that the DX-WPI-SP microcapsules can exhibit great potential in the food processing field.

Biotransformation of linoleic acid into different metabolites by food derived Lactobacillus plantarum 12-3 and in silico characterization of relevant reactions.

Lactic acid bacteria have been reported to be capable of converting polyunsaturated fatty acids, e.g. linoleic acid (LA) into bioactive and other fatty acid metabolites that are not toxic to the bacteria themselves, but the mechanism of this conversion is not clear. Here we reported for the first time that probiotic L. plantarum 12-3 derived from Tibet kefir when supplemented with LA from 1% to 10% in the MRS medium transformed LA to various fatty acid derivatives. These derivatives formed in the medium were identified with gas chromatography and mass spectrometry. In silico studies were done to confirm the enzymatic reactions responsible for this conversion. We found that L. plantarum 12-3 could convert LA at different concentrations to 8 different fatty acid derivatives. Putative candidate enzymes involved in biotransformation of LA into fatty acid derivatives were identified via whole genome of L. plantarum 12-3, including linoleate isomerase, acetoacetate decarboxylase and dehydrogenase. Therefore, the present study provides further understanding of the mechanism of conversion of LA to health-beneficial fatty acid metabolites in probiotic L. plantarum, which can be explored for potential application in functional foods.

Starch/tea polyphenols nanofibrous films for food packaging application: From facile construction to enhance mechanical, antioxidant and hydrophobic properties.

Starch based food packaging has been receiving increasing attention. However, the inherent poor properties of starch restrict its practical applications in the versatile material science field. In this study, a fast, simple, and environmentally friendly route to construct polyfunctional starch/tea polyphenols nanofibrous films (STNFs) by one-step temperature-assisted electrospinning was developed. The effects of introduction of tea polyphenols (TP) on the mechanical and antioxidant activity of STNFs were comprehensively investigated. Results of ABTS·+ free radical scavenging assay showed that the antioxidant activity of STNFs was endowed by addition of TP with optimum mechanical properties confirmed by tensile test. More interestingly, the hydrophobicity of STNFs was improved dramatically with increasing cross-linking time as indicated by water contact angle (WCA) measurement showing no effect on the antioxidant activity of the films. The results of this work offer a major step forward to promote functional starch-based materials for sustainable application in food packaging.

Effect of Incorporating Stevia and Moringa in Cookies on Postprandial Glycemia, Appetite, Palatability, and Gastrointestinal Well-Being.

BACKGROUND: Medicinal plants including stevia and moringa constitute an important source of health-beneficial bioactive components, and hence their intake may beneficially modulate biomarkers of chronic diseases. OBJECTIVE: The objective of the present study was to investigate the effect of incorporating stevia and moringa leaf powder in cookies on postprandial glycemia, appetite, palatability, and gastrointestinal well-being in humans. METHOD: In a randomized crossover design, 20 healthy subjects consumed 3 isocaloric test foods (each providing 50 g available carbohydrates) of control cookies (CC) made from 100% wheat flour, cookies containing stevia leaf powder (SC, 3% w/w), and cookies containing moringa leaf powder (MC, 5% w/w) as breakfast. Blood glucose and subjective appetite were measured at fasting and at 15, 30, 45, 60, 90, and 120 min after the consumption of the cookies. Palatability and gastrointestinal well-being were measured using standard questionnaires. RESULTS: Compared to CC, MC resulted in a significant decrease in postprandial blood glucose concentration at 30 and 45 min (p = 0.002 and p = 0.003, respectively) and showed a tendency (p = 0.077) for lower blood glucose incremental area under the curve (iAUC). Subjects were significantly less hungry after SC and MC intake (p = 0.035 and p = 0.041, respectively) compared to CC. All the cookies were liked by the subjects without any reported gastrointestinal discomfort. CONCLUSION: The results showed that compared to CC, MC improved postprandial glycemia and reduced hunger, while SC reduced hunger only. Future studies are now warranted to explore the mechanisms responsible for these observed effects.