To compare the effects of roasting pretreatment combined with different oil-extraction methods on the quality, antioxidant activity and volatile aroma of raw and roasted flaxseed oils.

Raw and roasted flaxseeds were used as materials, and oil samples were prepared by supercritical CO₂ extraction (SC-CO₂) and spiral pressing (SP). Their basic physicochemical properties, fatty acid composition, total phenol and tocopherol content,antioxidant activities [1,1-diphenyl-2-picrylhydrazyl radical (DPPH), 2,2’-azino-bis(3- ethylbenzothiazoline-6-sulfonate acid)diammonium salt cation (ABTS⁺) and ferric reducing antioxidant power (FRAP)] and volatile aroma components were determined, and the effects of different processing methods on oil quality were analyzed.

Both different oil-extraction methods and roasting pretreatment significantly affected the quality of flaxseed oil. The SP roasted group showed the highest iodine value, peroxide value and relative content of polyunsaturated fatty acids and total unsaturated fatty acids, reaching 178.00 g/100 g, 0.13 g/100 g, 69.56% and 89.61%, respectively. The untreated SC-CO₂ group e x h i b i t e d t h e h i g h e s t a c i d v a l u e a n d t o c o p h e r o l c o n t e n t, a t 2.0 0 m g/g a n d 3.96 mg α-TE/100 g, respectively. The roasted SP group had the highest total phenolic content (0.62 mg/g), which was not significantly different from that of the untreated SC-CO₂ group (0.60 mg/g, P>0.05). In terms of antioxidant activity,the untreated SP group exhibited the strongest ABTS⁺ radical scavenging capacity, whereas the SP roasted group showed the highest FRAP. Volatile aroma analysis indicated that roasting combined with SP promoted the accumulation of volatile compounds such as aldehydes, ketones, alcohols and pyrazines.

Roasting pretreatment and different oil-extraction methods significantly affects the nutritional quality, antioxidant activity and volatile aroma characteristics of flaxseed oil, providing a theoretical basis for optimizing flaxseed oil processing technology and its high-value utilization.

To establish a method for qualitative and quantitative determination of Asini Corii Colla in Ejiao Yishou oral liquid by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

The Ejiao Yishou oral liquid sample was digested with trypsin prior to HPLC-MS/MS analysis. A ZORBAX Eclipse Plus C₁₈ column (3.0 mm×150 mm, 1.8 μm) was adopted, using 0.1% formic acid aqueous solution-acetonitrile as mobile phase for gradient elution. Under the electrospray ionization mode, multi-reaction monitoring was carried out and the specific identification of Asini Corii Colla and the determination of the content of characteristic peptides of Asini Corii Colla were conducted.

The polypeptides derived from Asini Corii Colla exhibited good linearity relationships, with all correlation coefficients above 0.999. The relative standard deviations for instrumental precision,sample stability and method repeatability were all less than 4.0%, and the spiked recoveries at 3 concentration levels ranged from 88.30% to 100.22%. Asini Corii Colla was detected in all 126 batches of samples, while 91.3% of the samples had total content of the donkey-derived peptide A₁ and peptide A₂ below the proposed limit.

The established method is accurate, reliable and highly specific, and can be used for the quality control of Asini Corii Colla in the Ejiao Yishou oral liquid.

To explore the quality characteristics of Laoshan ancient tree sun-dried green tea in Malipo and analyze the internal correlations among physicochemical indexes, color, electronic sensory properties and artificial sensory evaluation.

The content of water extract, tea polyphenols, free amino acids, caffeine and catechins were determined in the sun-dried green tea water of ancient trees on the Laoshan of Malipo. A colorimeter, electronic nose and electronic tongue were employed to quantitatively characterize the color, aroma and taste of tea infusions,respectively followed by comprehensive analysis combined with artificial sensory evaluation.

The content of water extract, tea polyphenols and catechins in all samples were higher than the national standard GB/T 14456.2—2018 Green tea Part 2: Dayezhong green tea. The absolute values of the coefficients of variation for the polyphenol-amino acid ratio, a^* and sour, astringent, bitter and salty taste indicators all exceeded 30%. Principal component analysis extracted 5 principal components, which could be integrated into 3 core evaluation dimensions (physical and chemical constituents-taste, physical and chemical constituents-tea soup color and volatile aroma) and 2 secondary auxiliary dimensions, enabling effective quality discrimination of tea samples. Significantly positive correlations were found between free amino acids and sweetness, L^* and infusion color score, a^* and astringency as well as b^* and bitterness(P<0.05). Partial least squares regression analysis showed that the response values of b^* and W1C, W1W, W3S,astringency, bitter aftertaste, saltiness and sweetness made significant contributions to the artificial sensory score.

Laoshan ancient tree sun-dried green tea in Malipo exhibits excellent overall quality. The polyphenol-amino acid ratio, a^* as well as sour, astringent, bitter and salty taste indicators are the core factors driving quality differences. Tea quality is synergistically determined by water-soluble taste substances, color and aroma components, and precise quality evaluation can be achieved through principal component analysis.

To investigate the hepatotoxic effects of nano-sized and food-grade TiO₂ on mice liver.

A total of 80 Kunming mice was randomly divided into the control group and TiO₂ exposure groups with different particle sizes. The mice were intragastrically administered with nano-sized titanium dioxide (Nano-TiO₂) or food-grade TiO₂ (E171) suspension at doses of 50, 150 and 500 mg/kg BW for 14 consecutive days. Purified water was used as the negative control. At the end of the experiment related biochemical indexes were determined, the liver coefficient was calculated and liver antioxidant indexes were detected. Mice AML12 cells were treated with Nano-TiO₂ or E171 suspension at concentrations of 0, 25, 50 and 100 μg/mL, and cell viability and intracellular reactive oxygen species (ROS) content were subsequently measured.

After 14 days of exposure, neither nano-sized nor food-grade TiO₂ exerted significant effects on body weight, liver coefficient and liver-related biochemical indexes in mice. Nano-TiO₂ induced obvious oxidative damage in the liver of mice, while E171 had no significant influence on hepatic antioxidant indexes. In all dose groups, Nano-TiO₂ reduced cell viability and increased intracellular ROS levels.Decreased cell viability and elevated ROS content were only observed in the 100 μg/mL E171 treatment group.

Under the research same exposure conditions, the hepatic oxidative toxicity of Nano-sized TiO₂ is stronger than that of the food additive E171. This research provides a scientific basis for the safe application of food additive E171.

To establish a mothod for determination of oleuropein content in Oleaeuropaea L. related products by high performance liquid chromatography.

Ultrasonic-assisted extraction was employed to extract oleuropein from samples. The extraction conditions and mobile phase composition were optimized through single-factor experiments. The developed method was subjected to systematic method validation and subsequently applied to the determination of oleuropein content in commercially available products.

The optimal extraction conditions were 30% methanol with a solid-to-liquid ratio of 1:40 (g:mL), extraction temperature of 45 ℃ and extraction for 2 times. The chromatographic conditions consisted of acetonitrile-water (25:75, V:V) with a detection wavelength of 232 nm. Methodological validation demonstrated a good linear relationship (r²=0.999), and the precision [relative standard deviations (RSDs)<4%], repeatability (RSDs<3%) and spiked recovery (87.49%–115.00%) all met the required criteria.The oleuropein content in commercially available products typically ranges from 0 to 10 mg/g.

The method developed is highly sensitive and specific, can overcome complex matrix interferences, and is suitable for determining the content of oleuropein in Oleaeuropaea L. related products.

To determine the moisture retention rate, 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH)free radical scavenging rate, fatty acid content and volatile components composition of the Brassica oleracea var. italica seeds oil and sprouts oil respectively.

Gas chromatography-mass spectrometry (GC-MS) was employed to analyze the fatty acid profiles and volatile constituents of Brassica oleracea var. italica seeds oil and sprouts oil.

The main fatty acids in Brassica oleracea var. italica seeds oil were erucic acid (31.94%) and oleic acid (31.28%), with a total unsaturated fatty acid content of 84.07%. For sprouts oil, the predominant fatty acids were erucic acid (29.43%)and oleic acid (29.62%), and the total unsaturated fatty acid content reached 85.21%. In addition, 57 kinds of compounds were identified in brassica oleracea var. italica seeds oil. Alcohols were the most abundant class both in species and content, with 15 kinds of alcohol compounds detected; cubanol, propanol and butanol were the major alcohols, while ethanol was present at a low level. Tert-butyl alaninate was the most abundant ester. Only 3 kinds of aldehydes, namely hexanal, nonanal and 2-propenal, were detected. By contrast, 26 kinds of volatile compounds were identified in sprouts oil, which lacked olefins compared with seeds oil. Aromatic compounds were the most diverse and abundant components in sprouts oil, with 6 kinds of species detected, among which 1-benzylindole was the most dominant.Meanwhile, Brassica oleracea var. italica seeds oil also exhibited moisturizing and strong DPPH radical scavenging activity. The ability of Brassica oleracea var. italica seed oil to scavenge DPPH free radicals showed a significant dose-dependent effect. When the mass fraction was 10%, the scavenging rate could reach 97%.

Brassica oleracea var. italica seeds oil and sprouts oil possess high safety and distinctive flavors, supporting their further development and utilization.

To investigate the inhibitory effect of hyperoside on α-amylase and its mechanism of exerting hypoglycemic activity.

The inhibitory effect and type of hyperoside on α-amylase were evaluated via enzymatic kinetics. Fluorescence spectroscopy was used to observe the effect of hyperoside on α-amylase activity and its underlying mechanism. Molecular docking technology was employed to elucidate the molecular interactions between hyperoside and α-amylase from a microscopic perspective.

Hyperoside exhibited a significant inhibitory effect on α-amylase, with a median inhibitory concentration (IC₅₀) of 1.081 mg/mL. The inhibition type was identified as reversible mixed competitive and non-competitive inhibition. Hyperoside induced a fluorescence quenching effect on α-amylase, and the quenching mode was determined to be static quenching. With the increase in hyperoside concentration, the maximum emission wavelength of α-amylase showed a blue shift, indicating a change in its spatial conformation. Molecular docking results revealed that hyperoside could enter the cavity of α-amylase,competitively bind to the active site, and interact with amino acid residues (THR163A, LEU165A, TRP59A,GLN63A, ARG195A, HIS201A, GLU233A, ASP300A and HIS305A) through hydrogen bonds and hydrophobic interactions. The binding energy between hyperoside and α-amylase was –8.3 kcal/mol, indicating a tight binding.

Hyperoside forms a complex with α-amylase, thereby hindering enzymatic catalysis of substrates,further diminishing enzymatic activity, and ultimately contributing to its hypoglycemic effect.

To establish an electrochemical sensing method based on a copper oxide nanoparticle-modified electrode for the determination of carbendazim in foods.

The 3 kinds of modified electrodes were prepared by the drop-coating method. The screen-printed electrode (SPE) and the 3 kinds of modified electrodes were electrochemically characterized and screened by cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical response behavior of carbendazim on the surface of copper oxide nanoparticle-modified SPE (CuONPs/SPE) and the effects of scan rate were investigated by cyclic voltammetry. The supporting electrolyte and pH were optimized by differential pulse voltammetry, and the analytical performance such as the limit of detection and repeatability of the method was investigated.

The oxidation peak current of carbendazim on different electrode surfaces showed significant differences. Among them, CuONPs/SPE exhibited the largest oxidation peak current response. Under the optimal conditions, the oxidation peak current showed a good linear relationship with carbendazim concentration in the range of 0.1–200.0 µmol/L, and the limit of detection was 29.6 nmol/L.This method was applied to detect fresh shiitake mushrooms, fresh yam and grass carp samples. The spiked recoveries were 92.7%–113.9%, 84.9%–110.2% and 89.0%–93.5%, respectively.

The established CuONPs/SPE electrochemical sensing method has the advantages of simple electrode preparation, low detection cost and rapid response. It is suitable for the rapid determination of carbendazim content in various actual samples.