Food Chemistry: X最新文献

E-tongue, machine vision and NIR systems were used to standardize the quality measurements in twenty rice genotypes grown in Highland Himalayan regions of Kashmir, in order to overcome the constraints of manual measurements. IRCTN-312 showed highest amylose content of 20.74 % and 20.70 % using iodometric method and NIR tester, which was validated by the highest norm value of 34.158 by E-tongue. From these results, genotypes such as GSR-43, GS-103, GSR-23B, GSR-60, SR-4, GSR-46, Koshihikari, GSR-64, GSR-32, GSR-49, GSR-4, GSR-42, GS-459, SKUA-494 and SKUA-540 were classified as low amylose and C-3, K-332, M4–22 and IRCTN-312 were classified as intermediate amylose in the present study. Lowest percentage of damaged grains and chalk ratio was found in GSR-23B. SKUA-494 recorded highest L/W ratio using both the systems. Highest head rice yield and elongation ratio was found in GSR-23B and SKUA-494 genotypes respectively. Highest lightness (L*) value was recorded for Koshihikari genotype.

Plant-based meat analogs require improvements in taste and texture to better replicate traditional meat. L-theanine and tannin, abundant in green tea, influence food taste and physicochemical properties. This study evaluated the quality characteristics of green tea extract (GE)-supplemented plant-based patties (PP) and the mechanisms affecting taste and texture. Green tea was extracted with water (GWE) or 70 % ethanol (GEE). GEE contained higher tannin and lower L-theanine levels than GWE. Both GWE and GEE reduced protein deterioration and lipid oxidation in PP throughout the 28-day storage period. PP with 1.0 % GEE (PP-GEE1.0) showed improved emulsion stability and texture due to non-covalent interactions including hydrophobic interaction and hydrogen bonds, and increased β-sheet structures between tannin and pea protein. PP-GEE1.0 also had superior sensory characteristics due to an optimal balance of L-theanine and tannin. Overall, the incorporation of GE, particularly GEE significantly improved physicochemical properties, sensory quality, and storage stability of PP.

Thinned unripe kiwifruits (TUK) are considered the major agro by-products in kiwifruit production. To promote their potential applications, polyphenols and biological effects of unripe fruits from nine commercial kiwifruit cultivars were compared. Our findings showed that TUK were rich in bioactive polyphenols, which varied greatly by different cultivars. Indeed, catechin, epicatechin, procyanidin PB1, procyanidin B2, protocatechuic acid, neochlorogenic acid, and gallic acid were measured as the major phenolic components in most TUK, with the highest levels observed in ‘Hongao’ and ‘Cuiyu’ cultivars. Furthermore, TUK exerted strong in vitro antioxidant capacities, inhibitory effects on digestive enzymes, and anti-inflammatory activities. Particularly, their stronger antioxidant effects and inhibitory effects on digestive enzymes were probably attributed to their higher contents of phenolic compounds, especially procyanidin B2. Collectively, our findings reveal that TUK are potential resources of valuable polyphenols, which can be exploited as natural antioxidants and natural inhibitors of α-glucosidase and α-amylase.

Pericarpium citri reticulatae (PCR) has been used as a food and spice for many years and is known for its rich nutritional content and unique aroma. However, price increases are often accompanied by adulteration. In this study, two kinds of adulterants (Orange peel-OP and Mandarin Rind-MR) were identified by chromaticity analysis, FT-NIR and machine learning algorithm, and the doping concentration was predicted quantitatively. The results show that colorimetric analysis cannot completely differentiate between PCR and adulterants. Using spectral preprocessing combined with machine learning algorithms, PCR and two adulterants were successfully distinguished, with classification accuracy reaching 99.30 % and 98.64 % respectively. After selecting characteristic wavelengths, the R²_P of the adulterated quantitative model is greater than 0.99. Generally, this study proposes to use FT-NIR to study the adulteration of PCR for the first time, which fills the technical gap in the adulteration research of PCR, and provides an important method to solve the increasingly serious adulteration problem of PCR.

In this study, the dynamic changes of different anthocyanins in the processing of ‘Ziyan’ tea wine were investigated quantitatively. Results showed that six types of anthocyanins, namely petunidin, malvidin, pelargonidin, delphinidin, cyanidin and peonidin, as well as two co-pigmented substances, procyanidins and flavonoids, were detected in ‘Ziyan’ tea wine. As fermentation proceeded, the contents of petunidin, pelargonidin, delphinidin, cyanidin and peonidin decreased. Among them, petunidin, peonidin and pelargonidin showed a tendency of decreasing first, then increasing and finally decreasing, whereas delphinidin and cyanidin continued to decrease during fermentation. Variation trend of procyanidins and flavonoids was consistent with those of petunidin. Furthermore, metabolism of delphinidin, cyanidin and pelargonidin were main pathways responsible for the anthocyanin changes during ‘Ziyan’ tea wine processing. These findings suggested that the color of ‘Ziyan’ tea wine was achieved by the combination of various anthocyanins in different ratios and the co-pigmentation of procyanidins and flavonoids.

Ratiometric fluorescent films with high amine sensitivity and stability were developed to monitor the freshness of beef and pork. Fluorescein isothiocyanate (FITC) and red carbon quantum dots (R-CQD) were used as the amine-responsive indicator and internal reference, respectively. The electrospun films prepared by immobilizing FITC and R-CQD complex (F-R) into polyvinylidene fluoride (PVDF) under 35 %, 55 % and 75 % of relative humidity (RH) were named F-R@PVDF-1, F-R@PVDF-2 and F-R@PVDF-3, respectively. In comparison, the F-R@PVDF-2 film exhibited the highest sensitivity to trimethylamine (TMA), demonstrating a limit of detection (LOD) value of 1.59 μM, and meanwhile high stability during storage with ΔE value of 1.99 after 14 days of storage at 4 °C. The F-R@PVDF-2 film also showed a significant fluorescent red-to-brown color change during meat freshness monitoring at 4 °C. Conclusively, this study reported a new ratiometric fluorescent film that can be used to track the freshness of meats in food packaging.

In this study, the stems (ST) and leaves (LT) isolated from Large-leaf yellow tea (LYT) were used for sensory evaluation and quantitative analysis of flavor metabolites by sensomics and flavoromics. The results showed that the flavors of ST and LT in LYT were significantly different, and ST had stronger roasty and nutty aroma and sweet taste, which was mainly due to the accumulation of higher theanine and soluble monosaccharides in ST, and provided more substrates for the production of more pyrazine by the Maillard reaction; whereas LT contributed to the mellow and thick taste quality of LYT, and the abundance of catechins and caffeine were the main reason. The metabolic patterns of flavor metabolites indicated that the flavor differences between ST and LT were mainly due to biological metabolism in tea plants. This study provides the selection of raw materials for LYT in the future and product development of tea stems.

Glyphosate and glufosinate are the most widely used herbicides worldwide. We developed a simple and rapid analytical method for detecting glyphosate, glufosinate, and their metabolites (N-acetyl glyphosate: Gly-A, N-acetyl glufosinate: Glu-A, and 3-(hydroxymethylphosphinyl)propanoic acid: MPPA) in soybeans. The method involved extraction with water, trapping in a mini-column containing polymer-based resin with strong anion exchange groups, dehydration with acetonitrile, and solid-phase analytical derivatization at ambient temperature for 1 min using N-(tert-butyldimethylsilyl)-N-methyl trifluoroacetamide (MTBSTFA), followed by Liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination. This method offers a straightforward and rapid analysis, using on-solid phase dehydration and rapid derivatization at an ambient temperature with MTBSTFA, yielding reliable results for glyphosate, glufosinate, and their metabolites. The method was applied to both domestic and imported soybean samples. Glyphosate, glufosinate, and Glu-A were detected in imported feed soybeans and processed soybean meal for feed use, reflecting the current conditions of GM soybean cultivation.

The aim of this study was to explore the effects of freeze-thaw (FT) cycles on meat quality, myofibrillar protein gelation and emulsification properties, and exudate metabolome changes in pork loins. Meat tenderness improved (P < 0.05), whereas water-holding capacity (WHC), meat color attributes declined (P < 0.05) with FT cycles. Multiple FT accelerated meat lipid and protein oxidations. Decreases in strength and WHC of myofibrillar protein gels with FT cycles were confirmed. Myofibrillar protein emulsions with more FT cycles showed a decrease in the emulsifying activity index (P < 0.001) and larger oil droplets, resulting in poorer storage stability. A total of 501 metabolites were tentatively identified in pork exudates, with 21 metabolites significantly correlated (P < 0.05 and r > 0.6) with meat quality attributes. These results demonstrated the potential of using the metabolomic information from exudates to elaborate on or even predict the FT cycles, or meat quality.

Alginate-chitosan (Alg-CH) coated multiple water-in-oil-in-water (W/O/W) nanoemulsion loaded with sesamol and retinol was hypothesized to enhance the oxidative stability of margarine. Total phenol content (TPC), antioxidant activity, acid value (AV), peroxide value (PV), para-anisidine value (pAV), induction period (IP), and residual values of sesamol and retinol by HPLC were determined for 90 days. Margarine with tert-butylhydroquinone (TBHQ) (T3) had the higher TPC and antioxidant activity (8.05 mg gallic acid equivalent (GAE)/g), 53.1 %) than T1 (nanoemulsion, 7.39 mg GAE/g, 38.95 %), T2 (free-sesamol and -retinol, 6.98 mg GAE/g, 31.07 %), and T4 (no antioxidant, 6.46 mg GAE/g, and 14.45 %) while T1 had higher antioxidant activity and TPC than T2 and T4 after 90 days. On day 90, the highest residual values of sesamol (200.10 mg/100 g) and retinol (118.09 μg/100 g) obtained for T1. Overall, T1 contributed to the prolonged oxidative stability of margarine, potentially offering an alternative to synthetic antioxidants.