Search

Since the correlation between the overall aroma of in-shell walnuts and the volatile compounds existing in both their kernels and shells remained unclear, the odor profiles of roasted in-shell Xinjiang thin-shell walnuts including kernel and shell have been well investigated by sensory analysis, electronic nose, and HS-SPME/GC-MS, while volatile compounds were analyzed by multivariate statistical analysis of PLS-DA, variable importance projection (VIP) values and relative odor activity value (ROAV). Color and sensory evaluations confirmed the walnut shell did not change significantly after roasting, and it may have an odor-shielding effect on the kernel. Electronic nose could effectively distinguish the aroma difference of raw and roasted walnuts by signal intensities. A total of 94 volatile compounds were identified by GC-MS, and 31 odor-active compounds were recognized by further ROAV analysis. Although 2-methyl-furan with a spicy smoky aroma was increased in the roasted shell, benzaldehyde was raised in the roasted kernel with a bitter almond note, which played an important role in the roasted whole in-shell walnut odor. Overall, this study firstly explored the shell contribution to the whole odor of walnuts and illuminated the aromatic characteristics of in-shell roasting walnuts, which will provide a better understanding for the walnut processing and will be beneficial to the quality control for the roasted walnuts. [ABSTRACT FROM AUTHOR]

Background: Anthocyanins are a kind of flavonoids and natural water-soluble pigments, which endow fruits, vegetables, and plants with multiple colors. They are important source of new products with prebiotic activity. However, there is no systematic review documenting prebiotic activity of anthocyanins and their structural analogues. This study aims to fill this gap in literature.Purpose: The objective of this review is to summarize and evaluate the prebiotic activity of anthocyanin's, and discuss the physical and molecular modification methods to improve their biological activities.Study Design and Methods: In this review, the databases (PubMed, Google Scholar, Web of Science, Researchgate and Elsevier) were searched profoundly with keywords (anthocyanin's, prebiotics, probiotics, physical embedding and molecular modification).Results: A total of 34 articles were considered for reviewing. These studies approved that anthocyanins play an important role in promoting the proliferation of probiotics, inhibiting the growth of harmful bacteria and improving the intestinal environment. In addition, physical embedding and molecular modification have also been proved to be effective methods to improve the prebiotic activity of anthocyanins. Anthocyanins could promote the production of short chain fatty acids, accelerate self degradation and improve microbial related enzyme activities to promote the proliferation of probiotics. They inhibited the growth of harmful bacteria by inhibiting the expression of harmful bacteria genes, interfering with the role of metabolism related enzymes and affecting respiratory metabolism. They promoted the formation of a complete intestinal barrier and regulated the intestinal environment to keep the body healthy. Physical embedding, including microencapsulation and colloidal embedding, greatly improved the stability of anthocyanins. On the other hand, molecular modification, especially enzymatic modification, significantly improved the biological activities (antioxidant, prebiotic activity and so on) of anthocyanins.Conclusion: All these research results displayed by this review indicate that anthocyanins are a useful tool for developing prebiotic products. The better activities of the new anthocyanins formed by embedding and modification may make them become more effective raw materials. Our review provides a scientific basis for the future research and application of anthocyanins. [ABSTRACT FROM AUTHOR]

• pH-shifting was effective in reducing lectin allergy combining with autoclaving. • More hydrophobic exposures were confirmed in refolding process of pH-shifting. • β-turn increased and random coil decreased after the combining treatment. • Lectin aggregation was observed after autoclaving and enhanced with low pH treated. • Flexible structure and exposure of enzyme cutting sites improved digestibility. Combined effects of pH-shifting and an autoclaving cycle (121 °C, 15 min) on red kidney bean lectin (RKBL) were investigated using intrinsic and extrinsic fluorescence, UV, FTIR, DSC, SEC, dot-blot analysis and in vitro digestibility. Spectroscopic studies suggested that the protein refolding was stable after 3 h incubation with the hydrophobic exposure after pH-shifting, and hydrophobicity was significantly increased with the formation of more looser structure, which would influence the structural stability of known epitopes. In details, the increase of β-turn and reduction of random coil was related with the lower denaturation enthalpy, while the protein aggregation was also observed in acidic treated samples after autoclaving. Lower antigenicity and good digestibility suggested the exposure of enzyme cutting sites, and confirmed the effectivity of pH-shifting prior to the autoclaving. Then the results would be beneficial to the development of hypoallergenic kidney bean foods. [ABSTRACT FROM AUTHOR]

• Pre-germination was used to improve the nutritional value of brown glutinous rice. • Antagonism between ultrasound treatment and CaCl 2 stress was explored in soaking. • Both CaCl 2 and ultrasonic treatments improved GABA production during germination. • Energy metabolism, lipid metabolism and protein hydrolysis were enhanced. • Low-frequency ultrasound with salt stress would short the germinated time. In order to fortify γ-aminobutyric acid (GABA) of brown glutinous rice (BGR), pre-germination strategy was employed, and effects of low-frequency (28 kHz) ultrasound treatment combined with CaCl 2 stress on the sprout length, germination rate, morphology, color, water, total polyphenol content (TPC), starch, protein, GABA contents and relevant metabolites were investigated. The germination rate would be inhibited under CaCl 2 concentration ≥ 2.0 % during 24 h soaking without ultrasound treatment, and no significant difference was also observed combined with 9 h ultrasound treatment. Ultrasound treatment was beneficial to water absorption, TPC enrichment, energy metabolism, lipid metabolism and protein hydrolysis. Higher contents of GABA (3.29 folds), pyruvic acid (7.63 folds), glycerol (4.88 folds), glutamate (2.02 folds) and glucose (1.32 folds) were obtained due to the antagonistic effect between the 30 w ultrasound treatment and 2.0 % CaCl 2 stress at the 9 h pre-germination, and energy, lipid and protein metabolomic pathways were all involved in the GABA accumulation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Raw oils and enzymatic hydrolysis-thermal oxidation (ENTH) oils were prepared. • Corn, peanut, and olive oil after ENTH could better promote Maillard reaction (MR). • Coconut oil and palm oil had higher oxidation stability during MR processing. • Oleic acid and linoleic acid oxidation could promote the formation of aldehydes. • ENTH oils could reduce O, N, and S-containing heterocycles content in MR system. Vegetable oils with different unsaturated degrees (corn > peanut > olive > palm > coconut) and corresponding enzymatic hydrolysis-thermal oxidation (ENTH) oils were added into D-xylose and L-cysteine Maillard reaction (MR) system, respectively, for potential meaty aroma production. Results indicated that coconut oil and palm oil had lower peroxide, p -anisidine, total antioxidant values, and malondialdehyde content after ENTH and MR. Corn, peanut, and olive oils after ENTH could significantly promote MR because they caused the lower pH, higher reactants depletion, and higher browning degree in the water phase separated from the oil-Maillard reaction system. Additionally, the volatiles were mainly formed from oil phase. Corn, peanut, and olive oils were beneficial to volatiles formation in the oil-MR system due to fatty acid oxidation, especially oleic acid and linoleic acid. Meanwhile, compared to raw oils, adding ENTH oils to the MR system could reduce the content of oxygen, nitrogen, and sulfur-containing heterocycles. [ABSTRACT FROM AUTHOR]

• Two-step protocol with 70–80% (v/v) ethanol recover more prolamins from kidney beans. • MS data showed the composition diversity of prolamins from various kidney beans. • Seven prolamins were clustered into three main groups related to seed coat colors. • LSKB, BSKB, and RKB extractions have higher hydrophobicity and better OAC. • Hydrophobicity was related to the compositions and structures of prolamins. Ethanol protocol, two-step protocol and enzymatic extraction were used to extract prolamins from seven kidney beans (P. vulgaris L.) compared with Osborne protocol. 70–80% (v/v) ethanol concentrations were beneficial to the extraction, and two-step protocol was conducive to higher prolamin content. Varied protein subunits were observed in electrophoresis profiles, and further differences in composition were identified by LC-MS/MS while potential functions were annotated. Stronger hydrophobicity was found with prolamins enrichment from light speckled kidney bean (LSKB), black speckled kidney bean (BSKB), and red kidney bean (RKB), which was negative correlation with α-helix content based on the principal component analysis (PCA). The crude prolamins from the two kinds of white kidney beans possessed higher sulfhydryl and exhibited better water holding capacity (WHC), while higher oil absorption capacity (OAC) was observed in LSKB, BSKB, and RKB. Compared with zein, kidney bean prolamins could be used as food packaging materials due to hydrophobicity. [ABSTRACT FROM AUTHOR]