Phytochemical characteristics of citrus peel and effect of conventional and nonconventional processing on phenolic compounds: A review

Citrus peel is rich in functional ingredients such as essential oils (0.6–1%), fibers (6.30–42.13 g/100 g db), phenols (0.67–19.62 g/100 g db), and vitamin C (0.109–1.150 g/100 g db). Flavanones (hesperidin: 0.002–80.90 mg/g db, neohesperidin: 0.05–11.70 mg/g db, narirutin: 0.03–26.90 mg/g db; naringin: 0.08–14.40 mg/g db), and polymethoxylated flavones (sinensetin: 0.08–0.29 mg/g db, nobiletin: 0.20–14.05 mg/g db, tangeretin: 0.16–7.99 mg/g db) are the main phenolic compounds (PCs) of citrus peel. Due to their antioxidant activity, PCs are used in various applications such as formulation of healthy food, cosmetic, and pharmaceutical products. PCs present sensitivity to process operating conditions (during juice processing and further thermal and nonthermal processing). This review summarizes the main publications dealing with the proximate chemical composition, the functional properties, and the potential applications of the main citrus peel compounds. The effects of conventional and nonconventional processing on PCs of citrus fruits and their derived and coproducts are analyzed. The information provided in this review allows a better choice of appropriate processes and their optimal operating conditions for a better retention of antioxidants in citrus products.     

Effects of pulsed thermosonication treatment on fungal growth and bioactive compounds of Berberis vulgaris juice

In this study, the single and combined effects of pulsed‐ultrasound amplitude (100 W, 30 kHz with 25 and 50% amplitude levels for up to 30 min) and temperature (65 °C and 75 °C) on fungal growth, total phenolics, flavonoids and antioxidant activity of Berberis vulgaris juice were investigated. The combination of pulsed ultrasound at 50% amplitude for 30 min at temperature of 75 °C as the most effective treatment was resulted in a reduction of about?3.083 ± 0.02, ?3.04 ± 0.03, ?3.10 ± 0.01 and ?2.88 ± 0.02 log (N/N₀) on S. cerevisiae, A. flavus, A. versicolor and B. fulva, respectively. Additionally, the highest total phenolics, flavonoids and antioxidant activity were noted for the barberry juice after 30 min of sonication with 50% pulsed‐ultrasound amplitude at either 65 °C or 75 °C. Pulsed thermosonication is a promising technology to extend the shelf life of B. vulgaris fruit juice because of the improvement of antioxidant activity as well as microbial quality.     

淀粉-多酚复合物理化及功能特性的研究进展

近年来,利用食品成分间的相互作用来调节食物的感官与功能特性已成为食品学科的研究热点。多酚与淀 粉的相互作用在食品中普遍存在,多数情况下可赋予食品优良特性并产生一定的功能效应。本文综述了国内外关于 多酚与淀粉间相互作用的研究进展,介绍了淀粉-多酚复合物的形成机理和模型,并对复合物中淀粉的理化特性、 消化特性以及多酚的包埋特性进行了探讨。淀粉与多酚类化合物的相互作用不但可以提高淀粉的抗消化性,而且能 够提高多酚的生物利用率,为开发能够预防、控制高血糖症等的功能性食品提供一定的理论依据。     

莲子发芽对其功能及化学特性的影响

将莲子浸泡于水中,放置不同时间(24、36h和48h)和温度(25℃和35℃)促进其发芽,以未发芽莲子为空白对照,比较发芽种子化学和功能特性的变化。种子发芽导致胚乳中粗蛋白质和粗脂肪(P＜0.05)显著增加,而灰分和水分含量则没有可观测到的显著变化,其他成分除了植酸显著增加(P＜0.05)外,总酚、单宁和儿茶酚类物质的含量显著降低(P＜0.05)。发芽莲胚乳粉的吸水能力、吸油能力、乳化活性以及起泡性增加,而蛋白质溶解性下降(P＜0.05)。此外,发芽后莲心的总酚类化合物(P＜0.05)、总黄酮和酚类生物碱(甲基莲心碱、莲心碱、异莲心碱)含量都显著增加。因此,萌发可以增加莲子胚乳的营养质量和功能性质,而降低其抗营养性质,同样发芽能提高莲心酚类生物碱的含量。研究说明莲子发芽是改善莲子和莲心的营养质量好的方法。     

多酚复合材料的种类及应用研究进展

多酚复合材料是多酚与某种配合物通过共价键或非共价键相互作用合成的新型复合体.与多酚结合的配合物种类多样,尤以多糖、蛋白质、磷脂等生物大分子以及金属元素居多.通过合成多酚复合材料可显著改善某些天然多酚水溶性差、稳定性差、生物利用率低等问题,不仅可以增强多酚作为口服营养素或药物的靶向释放,还可以用作体外植物源抑菌剂,很大程...     

食品运载体系提高酚类物质生物利用度的研究进展

酚类物质已被证实具有降低冠心病、糖尿病、癌症和其他慢性疾病患病率的功能,近年来,如何将其作为生物活性物质应用到在食品和药品领域受到广泛关注。然而酚类物质的低水溶性、低稳定性、被动扩散方式以及在胃肠道环境中的损失限制了其在人体内的生物利用度。目前解除这些限制的最佳方法就是基于食品运载体封装技术对酚类物质进行包埋,这种方法已被证实可有效提高活性成分的稳定性和生物利用度。本文介绍了酚类物质的功能性质和评价其生物利用度的常见方法,对现有的运载体系及其在提高酚类物质生物利用度方面的应用现状进行综述,最后针对目前研究中存在的问题对未来酚类物质运载体系的研究方向提出合理建议。     

Changes in phenolics, γ-aminobutyric acid content and antioxidant,antihypertensive and hypoglycaemic properties during ale white sorghum (Sorghum bicolor (L.) Moench) brewing process

Effects of white sorghum brewing process on free amino-acids, γ-aminobutyric acid (GABA), phenolics and bioactivity, including antioxidant (by ABTS⁺ and reducing power, RP, methods), antihypertensive (angiotensin converting enzyme-I, ACE-I inhibition assay), and hypoglycaemic activity (α-glucosidase inhibition assay) were evaluated. From the wort to the beer, free amino acids decreased, but GABA and phenolics increased significantly, positively modifying the bioactive potential. ABTS and α-glucosidase inhibition activity correlated positively with at least one of the phenolic acids evaluated. Ale white sorghum beer presented high content of GABA (7.8 mg L⁻¹), phenolics (40.7 mg total phenolic acids L⁻¹), antioxidant activity (9.14 mmol Trolox equivalent L⁻¹, and 48.8 mmol ascorbic acid equivalent L⁻¹, for ABTS⁺ and RP, respectively), and exhibit ACE-I inhibition (1.0 μg captopril equivalent L⁻¹) and α-glucosidase inhibition (34.5 mg acarbose equivalent L⁻¹) activities. The level of bioactive compounds and its low ethanol content (2.3%), make beer obtained from malted white sorghum a potential functional beverage.     

Optimisation,characterisation and quantification of phenolic compounds in olive cake

The phenolic compounds in extracts from pressed olive cake were investigated. Free phenolic compounds were extracted from olive cake using methanol. To liberate bound phenolic compounds, the olive cake was subjected to basic and acidic hydrolysis followed by methanol extraction. The individual phenolic compounds and antioxidant activity of the extracts were determined. The highest total phenolic content and antioxidant activity were obtained using methanol extraction for 12 h at 70 °C. The RP-HPLC profiles for full-fat and defatted olive cake showed that protocatechuic acid, hydroxybenzoic acid, sinapic acid, p-coumaric acid, rutin and hesperidin were the predominant free phenolic compounds. Meanwhile, syringic acid, sinapic acid, caffeic acid and protocatechuic acid were the predominant bound phenolic acids. A positive correlation was observed between total phenolic content and antioxidant activity. The results indicated that most of the phenolic compounds in olive products were present in their free forms (75–90% of total phenolic content), while bound phenolic compounds were only a small proportion (10–25%) of total phenolic content.