Effects of ultraviolet C on the quality and aroma volatile in peach fruit during postharvest storage.

The study investigated the impact of UV-C irradiation on peach fruit quality during postharvest storage, with a focus on aroma changes and the mechanisms involving lipoxygenase metabolism. Results showed that UV-C irradiation at a dosage of 1.5 kJ/m2 was found to preserve the quality attributes of peach fruit during ambient storage, as evidenced by high flesh firmness, inhibition of weight loss and respiration rate, as well as high values of L* and ascorbic acid. Meanwhile, UV-C irradiation led to an increase in the contents of aroma-related volatiles, particularly esters and lactones, compared to non-irradiated fruit. Our results suggested that the enhanced emission of aroma-related volatiles in UV-C irradiated peach fruit was linked to elevated levels of unsaturated fatty acids. Besides, UV-C induced the expressions and activities of enzymes in the lipoxygenase pathway, thus promoting the synthesis of esters and lactones, which contribute to the enhanced aroma in peach fruit.

Optimization of fermentation conditions and quality evaluation of Chaenomeles sinensis glutinous rice wine.

The present study was conducted to optimize fermentation conditions for preparation of Chaenomeles sinensis Glutinous Rice Wine (CRW). The dynamic changes of main substances in the liquor during fermentation process, aroma components, biologically active substances and antioxidant capacity in the CRW after 6 months of aging were tested. The results showed that under optimized conditions, the yield and alcohol content of wine was 44.97 and 20.00%, respectively. After aging, 64 aroma components were detected in the wine, mainly alcohols and esters. The alcohol content of the CRW was 14.8%. Polyphenols and flavonoids reached 0.23 g/L and 0.037 g/L respectively. Furthermore, the CRW had an excellent free radical scavenging ability. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-024-05934-0.

Efficient degradation and enhanced α-glucosidase inhibitory activity of apricot polysaccharides through non-thermal plasma assisted non-metallic Fenton reaction.

Dielectric barrier discharge (DBD) was a commonly used non-thermal plasma (CP) technology. This paper aimed to enhance the biological activity of apricot polysaccharides (AP) by using dielectric barrier discharge (DBD-CP) assisted H2O2-VC Fenton reaction for degradation. The degradation conditions were optimized through response surface methodology. The molecular weight (Mw) of degraded apricot polysaccharides (DAP) was 19.71 kDa, which was 7.25 % of AP. The inhibition rate of DAP (2 mg/mL) was 82.8 ± 3.27 %, which was 106.87 % higher than that of AP. DBD-CP/H2O2-VC degradation changed the monosaccharide composition of AP and improved the linearity of polysaccharide chains. In addition, a novel apricot polysaccharide DAP-2 with a Mw of only 6.60 kDa was isolated from DAP. The repeating units of the main chain of DAP-2 were →4)-α-D-GalpA-(1 →, the branch chain was mainly composed of α-D-GalpA-(1 â†’ 2)-α-L-Rhap-(1→ connected to O-3 position →3,4)-α-D-GalpA-(1→. The complex structure formed by the combination of DAP-2 and α-glucosidase was stable. DAP-2 had a higher α-glucosidase binding ability than the acarbose. These results suggested that DAP-2 had the potential to be developed as a potential hypoglycemic functional food and drug.

Insights into formation and stability mechanism of V7-type short amylose-resveratrol complex using molecular dynamics simulation and molecular docking.

Pre-formed V-type amylose as a kind of wall material has been reported to carry polyphenols, while the interaction mechanism between V-type amylose and polyphenol is still elusive. In this work, the formation and stability mechanism of a V7-type short amylose-resveratrol complex was investigated via isothermal titration calorimetry, molecular dynamics, and molecular docking. The results presented that two stoichiometric ratios of resveratrol to short amylose were calculated to 0.120 and 0.800, and the corresponding main driving force was hydrogen bonding and hydrophobic interaction, respectively. The folding and unfolding conformation of V7-type short amylose chains appeared alternately during the simulation. Resveratrol tended to be bound in the short amylose helix between 40 ns and 80 ns to form a more stable complex. Hydrogen bonds between resveratrol molecule and O6 at the 22nd glucose molecule/O2 at the 24th glucose molecules and hydrophobic interaction between resveratrol molecule and glucose molecules (19th, 20th, 21st and 23rd) could be found.

Preparation and characterization of fine and stable short amylose nanocarriers for curcumin using a highly efficient and convenient method.

To prepare fine and stable nanocarriers for curcumin using a highly efficient and convenient method, nanoprecipitation combined with ultrasonication and a high-speed dispersion (US+HSS) method were used to prepare short amylose nanoparticles with pre-formed helical structures. Their morphology, structural characteristics, and embedding effects for curcumin were investigated. The results showed that the optimal ratio of ethanol to short amylose solution and ultrasonic time was 4:1 and 4 min, respectively. The nanoparticles showed a small size (82.43 nm), relatively high loading capacity (11.57 %), and a peak gelatinization temperature of 97.74 °C. Compared to the nanoprecipitation method, the short amylose nanoparticles prepared using the US+HSS method possessed a higher V-type crystalline structure ratio. In addition, the US+HSS method was easier to use to prepare nanoparticles with high stability against NaCl, and the stable nanoparticles showed the best in vitro sustained release effect for curcumin. The Peppas-Sahlin model was the optimal model that matched curcumin release from nanoparticles during digestion.

Improved encapsulation effect and structural properties of whey protein isolate by dielectric barrier discharge cold plasma.

The whey protein isolate (WPI) was modified by dielectric barrier discharge cold plasma (DBD) in order to improve its encapsulation efficiency of rutin. In this work, the effect of DBD treatment on structure and physicochemical properties of WPI and the interaction between DBD-treated WPI and rutin were investigated. The results showed that the structural change of WPI leaded to the exposure of internal hydrophobic groups, increasing the interaction site with rutin. The encapsulation efficiency of DBD-treated WPI (30 kV, 30 s) on rutin was improved by 12.42 % compared with control group. The results of multispectral analysis showed that static quenching occurred in the process of interaction between DBD-treated and rutin, hydrogen bond and van der Waals force were the main forces between them. Therefore, DBD treatment can be used as a method to improve the encapsulation efficiency of WPI on hydrophobic active substances.

Unravelling the Proteomic Profiles of Bovine Colostrum and Mature Milk Derived from the First and Second Lactations.

Bovine colostrum (BC) and mature bovine milk are highly nutritious. In addition to being consumed by adults, these dairy products are also used as protein ingredients for infant formula. However, the differences in the nutritional composition of BC and mature milk, especially regarding proteins present in trace amounts, have not been comprehensively studied. Furthermore, the distinct proteomic profiles of mature milk derived from the first lactation (Milk-L1) and the second lactation (Milk-L2) are not fully understood. To address these gaps, this study aims to uncover the subtle differences in protein compositions of BC, Milk-L1, and Milk-L2 by proteomics. Compared with BC, anti-microbial proteins ß-defensins and bovine hemoglobin subunit were up-regulated in Milk-L1, while Milk-L2 exhibited higher levels of enteric ß-defensin, sterol regulatory element binding transcription factor 1, sydecan-2, and cysteine-rich secretory protein 2. Additionally, immune proteins such as vacuolar protein sorting-associated protein 4B, polymeric immunoglobulin receptor (PIGR), and Ig-like domain-containing protein were found at higher levels in Milk-L1 compared with Milk-L2. The study provides a comprehensive understanding of the distinct proteomic profiles of BC, Milk-L1, and Milk-L2, which contributes to the development of protein ingredients for infant formula.

Color stability and degradation kinetics of anthocyanins in mulberry stirred yoghurt fermented by different starter cultures.

To evaluate the storage stability of anthocyanin in stirred yoghurt, mulberry juice and different starter cultures (S) were added into milk to investigate the color stability and degradation kinetics of anthocyanin. The result showed that the redness value decreased, while the brightness value increased, and the anthocyanin content decreased significantly from 1.47 ~ 1.86 to 1.01 ~ 1.19 mg/g. The degradation kinetics followed a first-order reaction. Principal component analysis showed that S2 and S6 were correlated with anthocyanins, S8 and S4 were correlated with a*. At the later stage, S4, S8 were correlated with a*, while S2, S4, S6 were correlated with anthocyanins. At 28th day, the anthocyanin content of S4 was 1.14 mg/g, which was not the highest, but the total score was the highest. Therefore, S4 was the best choice when the storage period is 28 days. This study provided technical support for the selection of a better starter for stirring yoghurt. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01271-8.

Intestinal Barrier Protective Study of Jujube Peel Polyphenols/Zein Complexes by a Combined Caco-2 Cell and Caenorhabditis elegans Model: A Perspective of Proteomics.

Jujube peels have been recognized as a promising resource of several bioactive ingredients. The main composition of jujube peel polyphenols (JPP) has been identified as rutin, kaempferol-3-O-rutinosid, and salicylic acid. The JPP/zein complexes, whose bioavailability reached 69.73% ± 5.06% in vitro, have been formed successfully. The Caco-2 cell and Caenorhabditis elegans (C. elegans) models have been combined to detect the intestinal barrier protective effect of JPP and its complexes. Results showed that JPP/zein complexes contain better protection capability than JPP in both models. In the Caco-2 cell model, the complex relieved intestinal barrier damage by regulating the tight junction proteins. Moreover, the lysosome pathway has been activated, further regulating immune responses and lipid transportation, improving the barrier function of C. elegans after incubation with JPP/zein complexes according to the proteomics study. This work provides new insights into intestinal barrier protection with bioactive compounds.

Low-temperature plasma modification, structural characterization and anti-diabetic activity of an apricot pectic polysaccharide.

To fully research the anti-diabetic activity of apricot polysaccharide, low temperature plasma (LTP) was used to modify apricot polysaccharide. The modified polysaccharide was isolated and purified using column chromatography. It was found that LTP modification can significantly improve the α-glucosidase glucosidase inhibition rate of apricot polysaccharides. The isolated fraction FAPP-2D with HG domain showed excellent anti-diabetic activity in insulin resistance model in L6 cell. We found that FAPP-2D increased the ADP/ATP ratio and inhibited PKA phosphorylation, activating the LKB1-AMPK pathway. Moreover, FAPP-2D activated AMPK-PGC1α pathway, which could stimulated mitochondrial production and regulate energy metabolism, promoting GLUT4 protein transport to achieve an anti-diabetic effect. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy data showed that the LTP modification could increase the CH bond content while decreasing the C-O-C/C-O bond content, indicating that LTP destroyed the C-O-C/C-O bond, which enhanced the anti-diabetes activity of the modified apricot pectin polysaccharide. Our findings could pave the way for the molecular exploitation of apricot polysaccharides and the application of low-temperature plasma.

Rheological properties, gel properties and 3D printing performance of soy protein isolate gel inks added with different types of apricot polysaccharides.

A soybean protein isolate (SPI)-apricot polysaccharide gel with hypolipidemic activity that can be used for 3D printing was prepared and the mechanism of its gel formation was studied in this work. The results demonstrated that adding apricot polysaccharide to SPI could effectively improve the bound water content, viscoelastic properties and rheological properties of the gels. Low-field NMR, FT-IR spectroscopy and surface hydrophobicity confirmed that the interactions between SPI and apricot polysaccharide were mainly realized by electrostatic interactions, hydrophobic and hydrogen bonding. Furthermore, adding modified polysaccharide treated by ultrasonic-assisted Fenton method to SPI on the basis of low-concentration apricot polysaccharide contributed to improving the 3D printing accuracy and stability of the gel. Consequently, the gel formed by adding apricot polysaccharide (0.5 %, m/v) and modified polysaccharide (0.1 %, m/v) to SPI had the best hypolipidemic activity (the binding rate of sodium taurocholate and sodium glycocholate were 75.33 % and 72.86 %, respectively) and 3D printing characteristics.

Green extraction of carotenoids from apricot flesh by ultrasound assisted corn oil extraction: Optimization, identification, and application.

The valorization of waste apricot flesh (WAF) can solve environmental and economic problems, and also meets the demand for natural pigments. Therefore, the aim of this paper was to recover carotenoids from WAF, to determine the type and content of carotenoids in the extracts and to explore the potential of the extracts for food industry applications. The extraction conditions were optimized. The total carotenoids content (TCC) was 42.75 mg/100 g dried weight under the optimized conditions: Time: 60 min, Temperature: 41.53℃, Power: 200 W, Liquid to solid (LS) ratio: 0.10 g/mL. The highest content of carotenoids in the corn oil extracts (COE) was phytoene. Color of COE under high temperature was investigated. Carotenoids in the COE were degraded at high temperatures. The a* of fries fried by COE was 7.31 times higher than that of corn oil. This study provides guidance for the green recovery of carotenoids and valorization of WAF.

Insight into the self-assembly behavior of α-zein by multi-spectroscopic and molecular simulations: An example of combination with the main component of jujube peel pigments - Rutin.

Zein has been widely used as a kind of carrier material for its self-assembly capability, while the mechanism of this process is still elusive. Rutin, one of the flavonoids, has been confirmed as the main ingredient of pigments in jujube peels. In this work, the binding mechanism in the zein/rutin complexes has been systematically studied by using multi-spectroscopic methods and molecular simulations. Results have shown that the encapsulation efficiency of complexes has researched the maximum, 67.30 % ± 1.50 %, when the concentration of rutin is 60 µM. Furthermore, the spherical morphology of complexes has been provided by microstructure characterization. Multi-spectroscopic indicated that a static quenching, alongside strong affinity, occurred in the process of interaction. Hydrophobic interaction has been further proven as the main force in zein/rutin complexes from the results of molecular dynamics simulation. This work is vital to fully utilize zein for the delivery of bio-compounds.

Fabrication and characterization of self-assembled whey protein isolate/short linear glucan core-shell nanoparticles for sustained release of curcumin.

The aim of this research was to prepare a bistratal nanocomplex with a high loading capacity (LC) and harsh environment stability for controlled release of curcumin (Cur) in gastrointestinal conditions. Whey protein isolate (WPI)/short linear glucan (SLG) core-shell nanoparticles were fabricated by self-assembly for the delivery of Cur. The results showed that Cur@WPI@SLG nanoparticles had a relatively high LC (12.89 %) and small particle size (89.4 nm). The nanocomplex remained relatively stable in extreme pH conditions (2-4 and 8-10), high temperatures (60-70 °C), and ionic strength (<400 mM). Core-shell nanostructures facilitated the sustained release of Cur in simulated gastrointestinal conditions. In addition, the nanocomplex had little cytotoxicity at high concentrations, yet significantly enhanced the DPPH scavenging activity and reducing power of Cur. This delivery system will significantly improve the sustained release effect of Cur and broaden the application of hydrophobic nutrients in foods.

Effects of ginkgolic acid(C15:1)on biofilm formation, pathogenic factor production and quorum sensing of Pseudomonas aeruginosa.

To complete the investigation of the bacterial inhibitory activity of ginkgolic acid (GA), the quorum sensing activity of GA was investigated to assess the potential of ginkgo biloba exocarp for the production of quorum sensing inhibitor. The effect of GA (C15:1) on the growth and secondary metabolism of p. aeruginosa PAO1 were tested. The results showed that GA (C15:1) had no effect on the growth of p. aeruginosa PAO1, and that GA (C15:1) was able to inhibit the formation of quorum sensing dependent virulence factors, but promoted the formation of biofilms. Finally, the above experimental results were verified by LasR-GFP, RhlR-GFP system and fluorescence quantitative PCR. These results suggested that GA (C15:1) was capable of modulating the quorum sensing system of p. aeruginosa PAO1 and possessed potential as an anti-virulence factor drug, but is not suitable for development as a broad-spectrum biofilm inhibitor.

Preparation of anthocyanin-rich mulberry juice by microwave-ultrasonic combined pretreatment.

The work aims to study the process of microwave-ultrasonic combined treatment to obtain anthocyanin-rich mulberry juice. A Box-Behnken design was employed to analyze the effects of microwave time and citric acid content on the total phenol content, total anthocyanin content, hue, color intensity, DPPH and ABTS radical scavenging activities. Under the optimum conditions (microwave time of 46 s, citric acid addition of 273 mg/kg), the total phenol content, total anthocyanin content, the DPPH and ABTS radical scavenging activities reached 4.24 mg GAE/mL, 3.29 mg C3G/mL, 4.59 mg TE/mL and 11.90 mg TE/mL, respectively. Subsequently, the mulberry juice was processed with ultrasound of different frequencies. It was found that low-frequency ultrasonic treatment (25 kHz) could significantly reduce the loss of total phenolic and anthocyanin monomers and improve the antioxidant capacity of mulberry juice during storage for five weeks. Overall, mulberry juice with microwave-ultrasonic pretreatment is a natural antioxidant.

Proteomic analysis reveals the mechanism of green regulation in garlic puree induced by purple light stress.

Greening is an undesirable appearance in garlic puree during processing. Our previous study indicated that purple light could induce the greening changes in garlic. In order to investigate the mechanism of green regulation in garlic puree, purple light-induced greening and nongreening garlic puree were used as materials to investigate the differentially expressed proteins (DEPs) by sodium dodecyl-sulfate polyacrylamide gel electrophoresis and data-independent acquisition (DIA) technology. The results showed that a total of 186 DEPs were detected by DIA, with 73 DEPs were up-regulated in greening garlic puree and 113 of them were down-regulated in greening garlic puree. Most DEPs were belonged to 20 functional categories, and mainly participated in post-translational modification and transport of proteins, molecular chaperones (12.93%) and signal transduction mechanisms (10.20%), energy production and transformation (6.80%), carbohydrate transport and metabolism (5.44%) and amino acid transport and metabolism (4.08%), indicating that the biological metabolic pathway, metabolic direction, and metabolic strength efficiency significantly changed in garlic puree after greening. Besides, the physiological and biochemical experiments showed that purple light significantly induced the γ-glutathione transpeptidase activity and prompted the conversion of thiosulfinate into garlic green pigment. This study explained the general molecular mechanism of greening changes of garlic puree in response to purple light. Practical Application Greening is an undesirable appearance in garlic puree during processing, which deteriorate the qualities of garlic. This study provides a comprehensive understanding of green regulation in garlic puree based on proteomics analysis.

Effect of color protection treatment on the browning and enzyme activity of Lentinus edodes during processing.

Fresh Lentinus edodes (L. edodes) are prone to browning (including enzymatic and nonenzymatic browning), which affects their quality and leads to economic losses during later processing. This study explored various effective color protection methods (color protection reagent and/or blanching) for inhibiting the browning of L. edodes. First, a single-factor experiment and a response surface method were used to optimize the concentration of the color retention reagent. The compound color retention reagent (comprising 0.1% phytic acid, 0.8% sodium citrate, and 0.5% d-sodium erythorbate) had the smallest total color difference (ΔE) value, suggesting that the compound color reagent had a better inhibiting effect than the single agent. Following this, the blanching conditions were studied; the polyphenol oxidase (PPO) activity was the lowest when the blanching temperature was 90°C and blanching time 180 s, indicating that browning is likely to be minimal. Finally, comparing the oxidase activity and total color difference (ΔE) revealed that combining the two color protection methods inhibits browning better than using a single method (color protection reagent or blanching). In addition, the polysaccharide and vitamin C (VC) contents of L. edodes under optimal color protection conditions were determined, which were 0.96 and 2.54 g/100 g fresh weight (FW), respectively. The results demonstrated that this color protection method effectively inhibits browning, reduces the nutritional loss, and improves the quality of L. edodes.

Enhanced extraction of bioactive natural products using ultrasound-assisted aqueous two-phase system: Application to flavonoids extraction from jujube peels.

The ultrasound-assisted aqueous two-phase extraction (UA-ATPE) was employed to develop an effective technique for the extraction of flavonoids from jujube peels (JPs). The extraction conditions were further optimized as K2HPO4 35% (w/w), ethanol 20% (w/w), solid-liquid ratio 1:30 g/mL (w/v), ultrasonic power 200 W, and extraction time 50 min. Moreover, rutin, quercetin 3-ß-d-glucoside, and kaempferol-3-O-rutinosid were identified as the main flavonoids by UPLC-MS/MS. Finally, the extraction mechanism of UA-ATPE was explored, which is salting out effect, hydrogen bonding, van der Waals force, and ultrasound promoted the mass transfer of solvent to cells of JPs, then extraction behavior occurred. The mechanical destruction of JPs cells by ultrasound also further accelerated the release of flavonoids. Flavonoids were captured by W/W emulsion in the bottom phase and distributed to the top phase. Overall, this study proposes a green and clean method, UA-ATPE, to extract flavonoids from JPs, while revealing the mechanism of UA-ATPE.

Preparation of Monascus-fermented ginkgo seeds: optimization of fermentation parameters and evaluation of bioactivity.

In this study, a high monacolin K yield was achieved through solid-state fermentation of Ginkgo biloba seeds. Monascus purpureus suspension made from red yeast rice was used as spore inoculum. Fermentation conditions in solid-state fermentation were optimized using response surface methodology, and the optimal conditions for the maximum monacolin K yield (17.71 ± 1.57 mg/g) were 0.22% ammonium sulfate, 0.34% ammonium chloride, 0.05% magnesium sulfate, fermentation time of 12 days, inoculation volume of 11%, and temperature of 27 °C. The total phenolic content of Monascus-fermented ginkgo seeds attained 9.67 mg GAE/g, 4.88-fold higher than that of unfermented ginkgo seeds. The scavenging abilities of DPPH and ABTS free radicals increased to 9.79 mg TE/g and 13.92 mg TE/g, respectively. These findings highlight the importance of investigating the optimal fermentation conditions for maximum monacolin K yield and the utilization value of ginkgo seed as fermentation substrate for higher bioactivities. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01078-z.