Hydroxycinnamic acids on gut microbiota and health

Hydroxycinnamic acids (HCAs) are a major class of phenolic acids with the characteristic phenylpropanoid C₆-C₃ backbone. Its typically conjugated status with plant cell wall components and liberation by limited enzymes might be the reason for its neglect by researchers compared to flavonoid-type polyphenols. The polyphenol–gut microbiota interactions and their impact on human health have captured the interest of researchers recently. In addition, there has been a significant progress over the past few years in understanding the gut microbiota-modulating effect of HCA using animal model studies. This review discusses the metabolism of HCA in the digestive tract, HCA–gut microbiota interactions, and its link to colorectal cancer, inflammatory bowel diseases, mental-cognitive impairments, nonalcoholic liver disease, and obesity. The effects of food matrix and processing technologies on HCA bioavailability and HCA–gut microbiota interactions, and HCA safety concerns are also featured in this review. This paper has provided an in-depth insight on HCA–gut microbiota relationship and identified the current literature gaps for future research.     

Improving storability,physiological disorders,and antioxidant properties of ‘Bartlett’ and ‘d’Anjou’ pears (Pyrus communis L.) by pre-harvest 1-methylcyclopropene spraying

Ethylene continues to be a major factor influencing quality of European pears during storage. Although research has been done on the effect of pre-harvest 1-methylcyclopropene (1-MCP) on physiological characteristics in pears, a full understanding of cultivar response and antioxidant metabolism remains elusive. Spraying 1-MCP on ‘Bartlett’ and ‘d’Anjou’ pears was studied with respect to physiology, storage and eating quality, disorders, and antioxidant properties at two harvest date (H1 and H2) during storage and ripening. Treatment with 1-MCP extended the harvest window of ‘Bartlett’ and ‘d’Anjou’ pears 3 and 4 days, respectively, without reducing storage or eating quality. Treatment with 1-MCP reduced ethylene production (EPR) and respiration rates (RR), maintained fruit firmness and green colour during storage and retarded development of desirable melting texture in both cultivars. Additionally, 1-MCP lowered the incidence of disorders by alleviating membrane lipid peroxidation, retaining high total flavonoids (TF) and antioxidant capacity, and enhancing superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activity in both cultivars. Overall, pre-harvest 1-MCP applications could extend storage time of ‘Bartlett’ and ‘d’Anjou’ pears to 5 and 6 months, respectively, at −1.1 ± 0.5 °C, by reducing ethylene synthesis and enhancing antioxidant metabolism.     

Grape skin extracts as a sustainable source of antioxidants in an oil-in-water emulsion: an alternate natural approach to synthetic antioxidants using principal component analysis

Grape (Kyoho) skin, used to retard lipid oxidation in edible oil foods, was investigated to reduce lipid oxidation in an oil-in-water (O/W) emulsion during 20 day of storage. The antioxidant efficacy of Kyoho skin extracts in O/W emulsions was determined by the measurement of secondary oxidation products. Moreover, principal component analysis (PCA) was conducted to determine similarities between emulsions treated with or without Kyoho skin extracts and standards. The data revealed that Kyoho skin extracts exhibited >93% inhibition and reported a similar p-anisidine (4.30–20.71) and TBARS (6.08–11.15 mg MDA L⁻¹) values over the standards during 20 day of storage. PCA (PCs 1 (51.83%) and 2 (18.85%)) demonstrated a similarity in the contribution of Kyoho skin extracts over the synthetic antioxidants in O/W emulsion. Overall, these findings highlighted the possibility of using Kyoho skin extracts as natural antioxidants to decrease oxidative rancidity in foods.     

The production of volatile compounds in model casein systems with varying fat levels as affected by low-frequency ultrasound

The effects of low-frequency ultrasound on the production of volatile compounds in model casein protein systems containing various fat concentrations of 2%, 4% and 6% (w/w) were investigated. Ultrasound application was performed at 20 kHz for up to 10 min which corresponded to energy densities ranging from 9.54 to 190.8 J mL⁻¹. Similar volatile compounds were detected both in pure fat and mixtures of casein and fat (CF) systems. These volatiles belonged to the groups of aldehydes, ketones, esters, alcohols and hydrocarbons, which were the products of oxidation of lipids or protein degradation due to acoustic cavitation. The amount of fat in the casein systems had minor effects on the production of volatiles, whereas the production of volatile compounds was significantly affected by the ultrasound treatment. Short sonication times <5 min generated similar volatile profiles to the untreated samples. In contrast, prolonged sonication for 5 and 10 min considerably increased the production of volatile compounds and the amounts of fatty acids. Thus, the application of low–frequency ultrasound for short periods should be considered to minimise the production of volatile compounds which can ultimately affect the taste.     

凯里红酸汤对大鼠肠道脂肪酸吸收和紧密连接蛋白的调控

通过灌胃摄入的方式观察贵州凯里红酸汤对高脂血症大鼠模型的小肠上皮脂肪酸吸收蛋白和紧密连接蛋白的调控作用。摄入凯里红酸汤期间测量大鼠的体质量和血脂,摄入11周后测定大鼠小肠上皮的脂肪酸转位酶CD36（FAT/CD36）、脂肪酸转运蛋白（FATP4）、紧密连接相关蛋白Occludin和紧密连接跨膜蛋白ZO-1的表达。结果表明,在高脂血症大鼠模型中,酸汤干预使大鼠的体质量和血脂显著降低（P＜0.05）,CD36和FATP4表达水平显著降低（P＜0.05）,ZO-1表达水平显著升高（P＜0.05）,其水平更接近于正常条件下喂养的阴性组大鼠。酸汤可以抑制大鼠体质量增长,恢复被高脂膳食破坏的小肠上皮紧密连接结构,减少肠道长链脂肪酸的吸收,改善大鼠高脂血症的状况。     

陇西腊肉传统制作过程中细菌群落演替对脂肪水解及氧化的影响

为探究陇西腊肉传统制作过程中细菌群落演替对脂肪水解及氧化的影响,采用Illumina MiSeq测序技术解析陇西腊肉制作过程中微生物群落结构及演替规律,并结合气相色谱-质谱联用技术检测制作过程中脂肪酸组成及含量变化,以及肉样中酸价、过氧化值的变化.结果表明:测序深度有效地覆盖了样品中绝大部分细菌种类,测序结果进行整理、...