Changes in contents of phenolic compounds during maturing of barrique red wines

Concentrations of derivatives of benzoic and cinnamic acids and furaldehyde were studied during maturing of a red wine (a mixture of Cabernet Sauvignon and Merlot) in barrique barrels (Quercus robur). Samples were taken at three-week intervals over 6 months. The influence of degree of toasting of the wood on the amount of phenolic compounds in barrique wine was also investigated. The samples were pre-separated using a solid-phase extraction on an RP 105 polymeric sorbent and analysed by high-performance liquid chromatography with UV-DAD detection. Gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic, benzoic and ellagic acids and p-hydroxybenzaldehyde, vanillin, 2-furaldehyde, 5-methoxy-2-furaldehyde and 5-methyl-2-furaldehyde were identified in the extracts of natural and toasted wood chips and in the extracts of the wine. Syringaldehyde was identified only in the extracts of the toasted wood chips. Ellagic acid can be regarded as a characteristic compound of barrique wine ageing and its constant level during some periods could become a marker of maturity of barrique wines. Due to the absence of furaldehydes in natural wines, these compounds can be considered as typical components of barrique wines and so they can serve as a marker of authenticity of barrique wines.     

Effects of postharvest UV‐C treatment on carotenoids and phenolic compounds of vine‐ripe tomatoes

Light red tomatoes were exposed to different doses of ultraviolet C (UV‐C) irradiation (1.0, 3.0 and 12.2 kJ m^?2). After treatment, the tomatoes were stored for 2 days at room temperature, and then analysed to determine the effect of irradiation on the main antioxidants, carotenoids and phenolic compounds and the results compared with the control samples. The lycopene content was found to have increased by 14% with respect to the control samples, while β‐carotene decreased. Cis‐isomers from lycopene also increased when the tomatoes were exposed to irradiation for more than 3 h. UV‐C irradiation also had a positive effect on total phenolic compounds; however, the same effect was not observed in the individually analysed phenolic compounds. While chlorogenic and ferulic acids increased in content, naringenin and rutin contents decreased. These results suggest that UV‐C irradiation of tomatoes could improve the beneficial effect of red tomatoes for human health by increasing the levels of certain bioactive compounds; it could also be used to obtain higher content of bioavailability components, such as cis‐isomers from lycopene.     

Changes in antioxidant capacity,isoflavone profile,phenolic and vitamin contents in soymilk during extended fermentation

In this study, the influence of lactic acid bacteria fermentation on the antioxidant capacity, phenolic compounds and vitamins profile of soymilk with different final fermentation pH values (pH 4.55, 4.15 and 3.85) was examined. Fermented soymilk (FSM) with a final pH of 3.85 exhibited relatively higher antioxidant capacity than samples terminated at pH 4.55 or 4.15, as shown from results of Folin–Ciocalteu assay (57.3–63.8 mg GAE/100 mL FSM), DPPH-radical scavenging efficiency (30.0–36.5%) and ferricyanide reducing power (1.13–1.58 mg AAE/100 mL FSM). Among all products, Lactobacillus rhamnosus WQ2-fermented soymilk showed the highest antioxidant level among the four Lactobacillus species, while Lactobacillus acidophilus CSCC 2400 possessed the best ability to deglycosylate isoflavone glucoside (IG), reducing IG concentration by 60.8%. Four vitamins, three phenolic acids, one flavanol, and six isoflavones were detected in fermented and non-fermented soymilk by HPLC-DAD. The contents of antioxidant compounds in FSM were closely related to reducing power and anti-radical ability. In addition, antioxidant capacity was highly correlated with proteolytic activity. This study also demonstrated the potential of extended fermentation to enhance the overall health-promoting property of the products.     

Changes in phenolic compounds, colour and antioxidant activity in industrial red myrtle liqueurs during storage

The results of a study on the evolution of phenolic compounds, colour and antioxidant activity in two industrial red myrtle liqueurs during storage in bottles under different bottle headspace (constant or increasing) and exposure to light are reported. In the year of the study, the phenolic compounds showed considerable changes even in the liqueurs stored with constant headspace. The anthocyanins in particular, both free and combined, tended to decrease. As expected, the same phenomena were observed in an accelerated form in the product stored in bottles with increasing headspace. The colour, evaluated according to the classic spectrophotometric parameters of intensity and hue, showed marked variability, especially in samples in which headspace was progressively increased. The two liqueurs showed antioxidant capacity values, expressed as mM of Trolox, comparable to those of red wine. They significantly decreased during storage in the bottles with increasing headspace, while values remained almost constant in the others.     

Changes in phenolic profile and antioxidant activity during production of diced tomatoes

Tomatoes and tomato-based products are rich in antioxidants such as carotenoids, vitamin C and polyphenols. The industrial processing of diced tomatoes involves heat treatments in which these antioxidant compounds may be potentially affected. In this study, we evaluate the effect of each separate step in the dice-making process. Three technological processes were investigated: Hot, Cold and Cold treated with calcium salt (CaCl₂). Four stages were monitored in each process: (1) fresh tomatoes; (2) peeled tomatoes; (3) diced tomatoes; and (4) final product after sauce addition. The main tool for minimising or counteracting the eventual processing damage was the strategy of ‘reconstitution’, achieved by adding a sauce rich in seeds and peels with high levels of antioxidants and phenolics to the diced tomatoes. Different analyses were carried out in order to evaluate the effect of each processing step. First, total polyphenols (TP) were evaluated using Folin–Ciocalteau (F–C) assay and antioxidant activity using ABTS⁺ and DPPH assays. Flavonols, flavanones, hydroxycinnamic and phenolic acids were then quantified using liquid chromatography/electrospray ionisation tandem mass spectrometry (HPLC–ESI–MS/MS). The combination of principal component analysis (PCA) and analysis of variance (ANOVA) revealed that each processing step induces alterations in the antioxidant and phenolic profile, and in particular sauce addition and calcium treatment significantly affected the levels of antioxidants and phenolics during the dice-making process.     

磁场对新鲜干红葡萄酒酚类物质影响的研究

为了缩短葡萄酒陈酿时间,使其品质在较短时间内得到改善,本文将磁场处理后的新鲜干红葡萄酒采用反相高效液相色谱法测定其黄烷-3-醇和酚酸两种酚类物质的含量,然后将这两种酚类物质含量的变化与其经自然陈酿后的变化相比较.研究结果表明,随着磁场处理时间的延长,5种黄烷-3-醇和11种酚酸的含量都发生了复杂的变化,且变化趋势基本符合自然陈酿效果.因此,磁场处理对于加速葡萄酒陈酿、提高葡萄酒品质是具有一定效果的.     

Changes in carotenoids during processing and storage of pumpkin puree

Changes in the contents of carotenoids and their true retentions (% TR) during the production of puree of Cucurbita moschata ‘Menina Brasileira’ and of Cucurbita maxima ‘Exposição’ pumpkins and the stability of such compounds during 180 days of storage were monitored by liquid chromatography coupled with a photodiode array detector. Cooking caused higher losses than commercial sterilisation. High losses of xanthophylls such as lutein and violaxanthin were noted during processing and storage of pumpkin puree. Such losses show the low stability of these compounds. The major carotenoids, pro-vitamin A carotenes, namely, α-carotene and all-trans-β-carotene for C. moschata ‘Menina Brasileira’ and all-trans-β-carotene for C. maxima ‘Exposição’ obtained high retentions (>75%) after processing. A slight degree of isomerisation of β-carotene was noted in the puree samples, but with low concentrations of cis-isomers. Storage for 180 days did not significantly affect (P ? 0.05) the concentrations of these carotenoids.     

Effects of processing on anthocyanins,carotenoids and vitamin C in summer fruits and vegetables

The purpose of this study was to evaluate the effects of processing, i.e. heating (98 °C, 10 min), freezing (−20 °C) and freeze-drying on anthocyanins, carotenoids, and vitamin C in summer fruits and vegetables, i.e. cherries, nectarines, apricots, peaches, plums, carrots and red bell peppers. The commodities were collected from growers located in the Otago region (namely Cromwell, Roxburgh, Mosgiel and Clinton), New Zealand. The results revealed that each commodity contained different contents of phytochemicals. The content and the process stability of phytochemicals in each commodity were influenced by the geographical location of the growers. In general, a high content of phytochemicals was found in summer fruits and vegetables grown in Otago compared to those grown in the Northern Hemisphere, e.g. anthocyanins in cherries, nectarines, peaches and plums; total carotenoids in red bell peppers and nectarines and vitamin C in cherries, peaches, red bell peppers and carrots. Heating and freezing enhanced the release of membrane bound anthocyanins, resulting in higher content after processing compared to fresh commodities. In the commodities studied, with the exception of red bell peppers, the stability of ascorbic acid was increased if ascorbic acid oxidase was inactivated for example by heating.     

Changes of phenolic compounds and antioxidant capacity in cocoa beans processing

A number of studies have shown that the consumption of cocoa and chocolate products has positive health effects on humans. The object of this research was to monitor changes of total and individual phenolics and antioxidant capacity during the cocoa bean manufacturing. The loss of cocoa phenolics and their antioxidant activity vary with the degree of technological process. The process of roasting and cocoa nib alkalisation had the major influence on phenolic compounds as well as on antioxidant capacity. The roasting treatment resulted in 14% loss of the total phenolics content, while alkalisation resulted in 64% loss of total phenolics content. Procyanidins B1 and B2 as well as (?)‐epigallocatechin were the unstable components, while caffeic acid derivate showed the greatest stability in all technological process. Furthermore, PCA showed that phenolic contents, antioxidant capacity and non‐fat cocoa solids parts of the samples were classified in groups according technological conditions.     

柑橘在贮藏加工过程中酚类化合物的变化

柑橘作为世界上最受欢迎的水果之一,富含类黄酮、酚酸等多酚类化合物,具有抗氧化、抗炎、抗癌、神经保护等多种生物活性。由于加工业和果品供应的需求,采后贮藏和深加工是柑橘产业化的必要手段,而在这过程中必然会导致柑橘酚类物质的变化。该文从营养学和功能食品学角度综述了柑橘果实在采后贮藏过程中和加工工艺条件下酚类化合物的变化规律及影响因素,适当早采、采摘前后物理化学处理及8℃～10℃、40 d条件下贮藏更有利于柑橘果实酚类物质的积累,干燥、发酵及冷杀菌工艺使柑橘加工体系中酚类化合物含量有所增加,而果实品种不同多酚物质变化无明确规律。该文旨在为保持柑橘营养品质稳定选择合理的贮藏及加工方式提供参考。     

加工温度对番茄和胡萝卜中类胡萝卜素含量的影响

目的:考察不同处理条件下,番茄和胡萝卜中类胡萝卜素含量的变化,指导人们采取合适的方法食用。方法:建立同时测定叶黄素、番茄红素和β-胡萝卜素的HPLC方法,测定常温、70℃和100℃时3种类胡萝卜素含量的变化。结果:在70℃时类胡萝卜素较稳定,温度达到100℃时则明显降解。结论:胡萝卜和番茄应熟食,以更好地吸收其营养成分,但加工温度应控制在70℃。     

Variations in the vitamin C content of imported tomatoes

An analysis was made of the vitamin C content of late winter tomatoes. A range of 6·8 to 31·2 mg reduced ascorbic acid per 100 g of fruit was observed in the batches of fruit examined in mid-March 1969. The mean value was 12·6 mg ascorbic acid per 100 g of fruit. It is emphasised that this mean figure was considerably lower than the 20 mg per 100 g given in McCance & Widdowson's (1967) ‘Tables of the Composition of Foods’ which are widely used in dietary surveys.     

Changes in taste compounds of duck during processing

Nanjing cooked duck is one of the few low temperature cooked meat products in traditional Chinese featured meat products. It is famous for its delicate processing, savoury, and tender flavour. Taste compounds of Nanjing cooked duck during processing, namely free amino acids, peptides and nucleotides, were analyzed. During boiling, both free amino acids and flavour nucleotides decreased significantly. Most peptides decreased during processing and the changes of total peptides were consistent with the nucleotides. Results showed that the special processes before boiling, especially brining, produced an increased of effect on the taste compounds, which could be the reason for the savoury taste of Nanjing cooked duck.     

香蕉皮中酚类和类胡萝卜素的国外研究进展

香蕉是世界四大水果、四大农作物之一,不仅用于鲜食和烹饪,还用于工业加工。香蕉皮约占香蕉鲜重的三分之一,在工业加工中常被废弃,造成资源浪费。目前已从香蕉皮中鉴定出多种活性物质,包括40余种酚类、10余种类萝卜素,此两类活性物质被证实具有抗氧化、抗菌、抗癌等功效。合理利用香蕉皮资源,不仅会为香蕉产业增加更多的附加价值,还能保护环境,符合可持续发展的战略要求。     

小麦发芽过程中酚类物质及其抗氧化活性的变化

以扶麦1228为研究对象,探讨小麦在发芽过程中酚类化合物成分和含量的变化,及其对抗氧化活性的影响。结果表明,发芽能显著提高小麦总酚含量(P0.01),且受到发芽时间的影响,发芽小麦的酚类化合物种类更加丰富,抗氧化活性更强,其中的酚类化合物主要包括咖啡酸、羟基酪醇、香草醛、对羟基苯甲酸、绿原酸、芹菜素、没食子酸、阿魏酸、芦丁、对香豆酸等。发芽能够促进小麦酚类化合物的形成,并提高其抗氧化活性,发芽小麦可作为一种潜在的天然抗氧化剂来源。     

西拉葡萄果实成熟过程中果皮内非花色苷酚类物质的变化

利用高效液相色谱-质谱联用(HPLC-MS)技术研究西拉葡萄果实成熟过程中果皮内非花色苷酚类物质的变化.结果表明:在葡萄成熟过程中共检测到27种非花色苷酚类物质,其中黄酮醇类物质舍量最高,黄烷-3-醇类次之.各类非花色苷酚类的含量在转色开始逐渐上升,到转色后1～2周达到最大值,随后缓慢下降;采摘前2周,除了酚酸类物质含量趋于稳定、白藜芦醇含量下降之外,其它非花色苷酚类物质含量再次升高.     

盐水鸭加工过程中滋味成分变化研究

该文采用高效液相色谱和氨基酸自动分析仪研究了盐水鸭加工过程中的滋味成分变化。盐水鸭加工过程中大部分小肽含量具有减少的趋势。在煮制前的加工中,游离氨基酸含量增加而风味核苷酸含量减少,煮制过程中两者的含量均显著减少。干腌后鸭肉含盐量最高,但经其后工序加工后含量降为适宜食用的3%左右。重要的滋味成分盐水鸭含量均高于对照鸭肉。风味核苷酸和鲜味氨基酸对盐水鸭的滋味具有重要贡献。盐水鸭加工过程中复卤工艺对鸭肉滋味成分作用显著,是构成盐水鸭美味的原因之一。     

Investigation of the contents of phenolic and alkaloidal compounds of gamma irradiated potatoes during storage

The contents of phenolic cinnamic acids and coumarins as well as of the glycoalkaloids of gamma irradiated potato tubers have been studied in detail. Gamma irradiation up to 3 k Gy had no effect on the glycoalkaloid contents of two potato tuber varieties during a four months storage period. The phenolic compounds behave differently and show a considerable change during storage in potatoes irradiated at the highest dose level, 3 k Gy. A time dependent change of phenolic extracts was observed. This change of phenolic compounds could be partly ascribed to the β-glycoside of scopoletin (coumarin, 7-hydroxy-6-methoxy) and was accompanied by a general decrease of chlorogenic acid, the main hydroxy-cinnamic acid of potatoes.     

Variation in contents of phenolic compounds during growth and post-harvest storage of pigeon pea seedlings

The variation in contents of seven phenolic compounds in pigeon pea seedlings during growth and storage was investigated. Maximum contents of vitexin, isovitexin and orientin were found in leaves growing 40 days, which were 0.99 ± 0.06, 6.63 ± 0.35 and 30.89 ± 1.92 mg/g DW. Apigenin and luteolin were extensively distributed in leaves, stems and roots. Pinostrobin and cajaninstilbene acid were mainly accumulated in leaves, the peak values 3.53 ± 0.18 and 2.49 ± 0.13 mg/g DW appeared at the 60th day. Slight and steady increases of seven phenolic compounds were found in room temperature (25 °C) stored pigeon pea leaves up to 120 days. The highest accumulation of seven phenolic compounds at chilling temperature (4 °C) was observed at the 45th day, after which the contents decreased sharply. The stems extracts exhibited more efficient DPPH radical-scavenging ability while the roots extracts demonstrated the strongest lipid peroxidation inhibitory activity.