Rapid Screening of Phenolic Compounds with Anti-Enteritis Activity from Camellia oleifera Oil Using a Smurf Drosophila Model and Molecular Docking Methods.

Screening and identifying the active compounds in foods are important for the development and utilization of functional foods. In this study, the anti-enteritis activity of ethanol extract from Camellia oleifera oil (PECS) was quickly evaluated using a Smurf Drosophila model and the metabolomics approach, combined with molecular docking techniques, were performed to rapidly screen and identify compounds with potential anti-enteritis activity in PECS. PECS showed good anti-enteritis activity and inhibited the activity of 5-lipoxygenase (LOX), cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS). In particular, wighteone and p-octopamine were newly identified in C. oleifera oil and were proven to have good anti-enteritis activity. The inhibitory activity of kaempferitrin (IC50 = 0.365 mmol L-1) was higher than that of wighteone (IC50 = 0.424 mmol L-1) and p-octopamine (IC50 = 0.402 mmol L-1). Of note, the IC50 value of salazosulfapyridine was 0.810 mmol L-1. Inhibition of LOX activity is likely one of the anti-enteritis mechanisms of PECS. These new findings lay the foundation for further investigations into the underlying mechanisms of anti-enteritis activity in C. oleifera oil.

Comparison of structural and in vitro digestive properties of autoclave-microwave treated maize starch under different retrogradation temperature conditions.

Retrogradation is a critical step in the physical production of resistant starch. This study aimed to examine the effects of isothermal and temperature-cycled retrogradation on the structural, physicochemical properties, and digestibility of resistant starch type-III (RS3) under various thermal conditions. To create RS3, normal maize starch (NM) and Hylon VII (HAM) were treated by autoclave-microwave and then retrograded at isothermal (4 °C) or various temperature conditions (4/10 °C, 4/20 °C, 4/30 °C, 4/40 °C, and 4/50 °C). We found that temperature-cycled retrogradation possessed greater potential than isothermal retrogradation for producing short-range ordering and crystalline structures of RS3. Also, retrograded starch prepared via temperature cycling exhibited higher double helix content, lower amorphous content, reduced swelling power, and less amylose leaching in water. Furthermore, the starch digestibility was affected by structural alterations, which were more significant in HAM-retrograded starch. While, HAM-4-40 (39.27 %) displayed the highest level of resistant starch (RS).

Study on the taste active compounds in Douchi using metabolomics method.

Douchi is a traditional famous seasoning in China. This study adopted electronic tongue and metabolomics to analyze the taste characteristics and taste active compounds of 12 samples from three most famous types of Douchi (Liuyang Douchi, Yangjiang Douchi, Yongchuan Douchi). Thirty-six differential metabolites mainly enriched from the arginine biosynthesis were identified among these Douchis. Umami and bitterness are considered as two taste that bring positive and negative perceptions for Douchi. The succinic acid was found to be responsible for the umami in LY, YJ and YC Douchi, with the TAVs of 2054, 643, 174, respectively, rather than the glutamic acid and aspartic acid. The leucine was identified as the main metabolite for bitterness, with the TAVs of 9, 9, 7 respectively. KEGG enrichment analysis found that the umami, sourness and saltiness might be related to alanine, aspartate and glutamate metabolism and the bitterness might be related to aminoacyl-tRNA biosynthesis pathway.

Identification of novel α-glucosidase and ACE inhibitory peptides from Douchi using peptidomics approach and molecular docking.

In this study, the effect of Douchi extract (DWE) on α-glucosidase and angiotensin-converting enzymes (ACE) were investigated, and several novel peptides with inhibitory activity against α-glucosidase and ACE were identified using peptidomics approach based on UPLC-MS/MS. The average inhibition rates of DWE on α-glucosidase and ACE were 73.75-78.10% and 4.56-27.07%, respectively. In the DWE, a total of 710 peptides were detected. Two novel peptides with potential inhibitory activity against α-glucosidase were identified using the correlation analysis, database alignment and molecular docking methods. They were DVFRAIPSEVL and DRPSINGLAGAN, with the IC50 values of 0.121 and 0.128 mg/mL, respectively. Also, four novel peptides with potential inhibitory activity against ACE were identified: PSSPFTDLWD, EEQDERQFPF, PVPVPVQQAFPF and PSSPFTDL, with IC50 values of 1.388, 0.041, 0.761 and 0.097 mg/mL, respectively. These results indicated that combining peptidomics and molecular docking is an effective alternative strategy for rapidly screening numbers of novel bioactive peptides from foods.

Rapid and Economic Determination of 13 Steviol Glycosides in Market-Available Food, Dietary Supplements, and Ingredients: Single-Laboratory Validation of an HPLC Method.

Steviol glycosides, obtained from leaves of Stevia rebaudiana Bertoni (stevia) or produced via bioconversion and biosynthesis, are diterpenes used by the food/dietary supplement industry as zero-calorie sweeteners derived from natural sources. JECFA 2017 is the most updated international standardized method but it runs for 80 min per sample with suboptimal separations on several critical pairs for its high-performance liquid chromatography-ultraviolet (HPLC-UV) determination. We developed and validated a rapid and economic HPLC-UV method using the superficially porous particle column to determine 13 steviol glycosides (stevioside, dulcoside A, rubusoside, steviobioside, and rebaudioside A-F, I, M, and N). Baseline separation with a minimum resolution of 1.5 for 13 steviol glycosides was achieved within only 14 min of separation time. The hydrocarbon stationary phase with additional steric interactions from the isobutyl side chains on the C18 ligand was shown to be an important contributor to chromatographic selectivity of several critical pairs of steviol glycosides. The method was proven to perform suitably on columns from three different manufacturers and two HPLC instruments. The method was further used to perform a single-lab validation on eight food and supplement products with multiple matrices. The results ranged from 0.05% w/w rebaudioside A for a hard-candy finished product to 100.8% w/w purity for a rebaudioside M raw ingredient. The validation test results showed that the method was linear, suitable, specific, accurate, and precise. The method is therefore suitable to be considered as a new industrial standard for quality control analysis for stevia products.

Synthesis of some glucose-fatty acid esters by lipase from Candida antarctica and their emulsion functions.

The synthesis of glucose esters with palmitic acid, lauric acid and hexanoic acid using lipase enzyme was studied and their emulsion functionality in oil-in-water system were compared. Reactions at 3:1M ratio of fatty acids-to-glucose had the highest conversion percentages (over 90% for each of the fatty acid). Initial conversion rate increased as substrate solubility increased. Ester bond formation was confirmed by nuclear magnetic resonance technique that the chemical shifts of glucose H-6 and α-carbon protons of fatty acids in the ester molecules shifted to the higher fields. Contact angle of water on esters' pelleted surface increased as the hydrophobicity increased. Glucose esters' and commercial sucrose esters' functionality as emulsifiers were compared. Glucose esters delayed, but did not prevent coalescence, because the oil droplets diameter doubled during 7days. Sucrose esters prevented coalescence during 7days since the droplets diameter did not have significant change.