样品预处理对测定葡萄酒中二氧化硫残留结果的影响

通过样品预处理.对现行国标GB/T5009.34-2003盐酸副玫瑰苯胺法测定葡萄酒中游离二氧化硫残留方法进行改进.样品先加氢氧化钠溶液释放亚硫酸盐,再加盐酸游离二氧化硫.该方法回收率82.5～87.5%,国标和改进后的方法测定结果经统计学处理精密度分别为0.027±0.008和0.033±0.004(P＜0.01).     

Effect of added sulphur dioxide levels on the fermentation characteristics of strawberry wine

The aim of this study to evaluate the effects of sulphur dioxide (SO₂) on strawberry wine fermentation and on the quality of the final wine product. Major aroma compounds, reducing sugars, ethanol, titratable acid and microflora were analyzed during the fermentation of strawberry wine supplemented with 0–100 mg/L SO₂. As the amount of added SO₂ increased, the consumption of reducing sugars and soluble solids and ethanol production decreased during early fermentation, but increased during late fermentation. During the fermentation process, the concentrations of 2‐phenethanol, isobutanol and isopentanol significantly increased and those of n‐propanol, isoamyl acetate and ethyl lactate decreased with increasing amount of added SO₂. The production of n‐butanol, ethyl acetate and ethyl butyrate was slightly dependent on the amount of added SO₂. Yeast cells were the dominant microbe in the fermenting strawberry pulp, and indigenous bacteria and fungi populations decreased rapidly or disappeared because of their sensitivity to SO₂. It was concluded that 60–80 mg/L SO₂ should be added during strawberry wine fermentations to improve wine quality. Copyright © 2016 The Institute of Brewing & Distilling     

添加洋葱汁和二氧化硫的赤霞珠红葡萄酒发酵的比较

SO2是葡萄酒酿造广泛使用的抑菌剂和抗氧化剂,由于对人体健康的负面影响,近年来有很多替代品的研究.该研究在赤霞珠红葡萄酒自然发酵和接种发酵中添加洋葱汁(50 g/L)和SO2(60 mg/L),通过测定发酵过程中微生物种群量、主要酿造特性、色度和氧化还原电位的动态变化,比较了洋葱汁和SO2的应用效果.结果表明,接种酵母...     

柿子酒中非花色苷酚物质的提取及组成分析

对柿子酒中非花色苷酚物质的组成进行分析,可以为柿子酒的生产和消费提供重要的参考。通过单因素和正交实验,对影响柿子酒中多酚提取量的提取时间、提取温度、料液比和提取次数四个因素进行探讨,确定了柿子酒多酚的提取工艺参数为:提取剂为100%乙酸乙酯,料液的体积比1∶3,在温度50℃下提取,每次35min,提取5次,多酚的提取量达到最大值375.28mg/L。利用高效液相色谱与质谱联用技术（HPLC-UV-MS）对柿子酒提取物进行分析,结果表明:柿子酒中主要非花色苷酚为没食子酸、儿茶素、水杨酸、没食子酸乙酯和丁香酸,其中没食子酸的含量最高115.56mg/L,丁香酸的含量最少0.64mg/L,其它三种物质的含量分别为8.41、5.35、2.23mg/L。      

White wine phenolics: current methods of analysis

White wine phenolic analyses are less common in the literature than analyses of red wine phenolics. Analytical techniques for white wine phenolic analyses using spectrophotometric, chromatographic, spectroscopic, and electrochemical methods are reported. The interest of research in this area combined with the advances in technology aimed at the winemaking industry are promoting the establishment of novel approaches for identifying, quantifying, and classifying phenolic compounds in white wine. This review article provides an overview of the current research into white wine phenolics through a critical discussion of the analytical methods employed. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

The enhancement of orange oil oxidation by sulphur dioxide

Reactions at 35°C of orange oil in contact with air and water were investigated by gas-liquid chromatography (g.l.c.) and by oxygen absorption measurements. Degradation of the orange oil was reduced in the presence of citric acid, but addition of sulphur dioxide caused a drastic increase, the extent and the rate of which were proportional to the initial concentration of the preservative. Several degradation products were identified.     

High-added-value antioxidants obtained from the degradation of wine phenolics by Lactobacillus plantarum

Disposal of the waste from wine production has long been a problem for wineries, mainly because of the presence of phenolic compounds. In this study, we analyzed the antimicrobial activities of 10 wine phenolic compounds against Lactobacillus plantarum strains. Inhibition increased in this order: catechin = gallic acid < epicatechin = salicylic acid < methyl gallate = caffeic acid < ferulic acid = tryptophol < p-coumaric acid. The obtained results indicated that L. plantarum is able to grow in the presence of high concentrations of some wine phenolic compounds. Of the 10 compounds analyzed, only the hydroxycinnamic acids, gallic acid, and methyl gallate were metabolized by the four L. plantarum strains studied. Results also revealed that 4-vinylphenol and 4-vinylguaiacol are originated from p-coumaric and ferulic acids. These phenolic compounds are valuable intermediates in the biotechnological production of new fragrances. In addition, gallic acid and its ester, methyl gallate, are metabolized to produce the powerful antioxidant pyrogallol. Therefore, it might be possible to use L. plantarum strains to obtain high-added-value antioxidants from the degradation of phenolic compounds found in wine wastes.     

Chemistry of sulphur dioxide in vegetable dehydration

The state of sulphur dioxide in partially dehydrated or dehydrated foods is complex and depends on pH, ionic strength, water activity and concentration, and on the effects of anions and cations on the solubilities of sulphite and disulphite salts. The chemical basis of the preservative action is explained in terms of the nucleophilicity of the sulphite ion and the possible consequences of the changing state of the additive during dehydration are evaluated. The significance of autoxidation of the sulphite ion to its fate in food, and role as an antioxidant, or prooxidant, is critically discussed. The most widely studied reaction of sulphur dioxide in food is its inhibition of non-enzymic browning; the current state of knowledge concerning the mechanism of this action is explained.
The loss of sulphur dioxide during vegetable dehydration obeys first-order kinetics. This observation is considered in terms of known first-order reactions in foods and processes which are limited by rate of diffusion. There are still insufficient data to suggest ways in which the composition of the food could be altered to reduce its requirement for sulphur dioxide during dehydration.     

Reactivity of vegetables towards sulphur dioxide

When Brussels sprouts, cabbage, carrot, peas and potato are dried in air at 80°C in the presence of sulphur(IV) oxospecies, S(IV), 51 ± 6% of the additive is lost, irrespective of the vegetable or the amount of S(IV) in the final product when present in the following amounts: Brussels sprouts, 800–2000mg SO₂/kg; cabbage, 260–1900 mg SO₂/kg; carrot, 270–1300 mg SO₂/kg; peas, 250 mg SO₂/kg; potato, 32–220 mg SO₂/kg.The reactivity, towards S(IV), of aqueous extracts of different vegetables is compared and assessed in relation to the total solids, glucose, fructose, amino-nitrogen and Kjeldahl-nitrogen contents of the extracts. It is suggested that the rate-limiting process in the loss of S(IV) during vegetable dehydration is not the reaction of reducing sugars with amines but is possibly some physical process.     

利用凯氏定氮仪快速测定葡萄酒中二氧化硫

目的建立使用凯氏定氮仪快速检测葡萄酒中二氧化硫的方法。方法利用凯氏定氮仪和全玻璃蒸馏法工作原理的相似之处,将凯氏定氮仪用于葡萄酒中二氧化硫的测定。对比了凯氏定氮仪蒸馏和全玻璃蒸馏法的空白实验,确定了使用凯氏定氮仪快速检测葡萄酒中二氧化硫合适的样品量、滴定碘溶液浓度、蒸馏时间,并进行了精密度实验、回收率实验。最后,以8种市售葡萄酒为实验材料对比了凯氏定氮仪法与全玻璃蒸馏法对二氧化硫含量的检测结果。结果凯氏定氮仪蒸馏和全玻璃蒸馏法的空白实验结果基本无差异。使用凯氏定氮仪进行葡萄酒中二氧化硫检测,其合适样品量为40 mL,滴定碘溶液浓度为0.1 mol/L或0.05 mol/L,蒸馏时间大大缩短,为8 min,RSD为1.36%,平均回收率为(102.40±3.26)%,且对8种市售葡萄酒样品的检测结果与全玻璃蒸馏法相比无显著性差异(P0.05)。结论凯氏定氮仪法测定葡萄酒中的二氧化硫,检测效率高,精密度好,准确度高,可作为葡萄酒中二氧化硫的批量检测方法。     

Food safety panel sulphur dioxide in foods

The following are summaries of four of the papers presented at a symposium on ‘Sulphur dioxide in foods’, organised by the Food Safety Panel of the Food Group. It was held on 22 October 1980 at the Society of Chemical Industry, 14 Belgrave Square, London, SW1X 8PS. The papers so published are entirely the responsibility of the authors and in no way reflect the views of the Editorial Board of the Journal of the Science of Food and Agriculture.     

The reactions of sulphur dioxide in dehydrated vegetables

The reactions of ³⁵S sulphur dioxide incorporated into laboratory dehydrated vegetables (cabbage, carrots, potatoes) from a sulphited scald liquor have been investigated. The results showed that immediately after dehydration only 35–45% of added sulphite was measurable as sulphur dioxide. The remainder of the added sulphite, apart from a small percentage which had been converted to sulphate, was present in the form of organic sulphur compounds.     

Effect of grape processing on selected antioxidant phenolics in red wine

Wine, particularly red wine, is an important source of polyphenols and several studies have shown that moderate wine consumption is associated with a reduced risk of coronary heart disease. It has been hypothesized that these antioxidant compounds may be responsible for the potential beneficial effects of wine. The influence of different vinification techniques (fermentation on skin [A], mash heating [B], and the combination of both [C]) on the antioxidant capacity and the phenolic composition of red wines (Spätburgunder [Pinot Noir], Lemberger, and Cabernet Franc) were tested in the present study. The highest concentrations of anthocyanins, flavan-3-ols, flavonols, stilbenes, and antioxidant capacity were found in the red wines which were produced under the conditions of C, followed by B and A.     

Effect of sulphur dioxide and must extraction on colour,phenolic composition and sensory quality of red table wine

Red wines were made during 1992 from Vitis vinifera var Roriz grapes using a high and a low level of extraction and three levels of total sulphur dioxide (0, 75 and 150 mg SO₂ kg⁻¹). From this single experiment, the effects of total SO₂ and extraction on anthocyanin composition and colour were observed by HPLC, spectrophotometry and tristimulus colorimetry. High extraction produced a wine with more total pigments and total phenols than low extraction and increased the amount of organic acids extracted during fermentation. More anthocyanins were extracted with increasing SO₂ levels. On maturation, all wines lost colour and increased in brownness. Wines made without SO₂ browned more than the wines made with SO₂. The anthocyanins normally present in wines were all rapidly lost to trace levels at 24 months. Vitisin A, a more stable and highly coloured anthocyanin than malvidin 3-glucoside, showed a slower decrease in concentration than malvidin 3-glucoside and contributed significantly to the wine colour during aging. At the first analysis, the wines made without SO₂ had a higher percentage colour due to polymers than the wines made with SO₂. Polymerisation progressed during maturation, although the initial differences were maintained. Sensory analysis after 6 and 18 months storage by expert tasters revealed differences mainly related to the colour attributes, indicating that when wines are made using modern hygienic techniques, total SO₂ has a negligible effect on aroma and flavour attributes. © 1998 Society of Chemical Industry.     

固相萃取-离子色谱法测定葡萄酒中二氧化硫

[目的]探索较为简便易行的葡萄酒中二氧化硫测定的方法。[方法]准确称取一定量的葡萄酒,过C18柱分离除去部分非极性有机物质后经滤膜过滤加入Na2CO3水溶液定容,进样后使用9mmol/LNa2CO3作为淋洗液,用离子色谱法测定葡萄酒中二氧化硫。[结果]二氧化硫呈现出较好的峰形且与其他离子能较好的分离。RSD均小于5%,回收率在93%～105%之间。[结论]葡萄酒中二氧化硫离子色谱测定方法的建立将为离子色谱测定液体食品中二氧化硫纳入国家标准提供了依据。      

连续流动分析法测定葡萄酒中总二氧化硫

目的建立连续流动分析仪测定不同类型葡萄酒中总二氧化硫检测的方法。方法样品在酸性条件下蒸馏,蒸馏液与甲醛及盐酸副品红反应生成红色络合物,连续流动分析仪在560 nm波长处自动检测。吸取样品并配制好相应的试剂后在流动注射仪上自动完成分析过程。结果与国家标准推荐的碘量法进行对比,RSD小于1.5%。同时测定了样品的加标回收,回收率为90%~105%,标准物质含量的检测结果在允许范围内。结论 连续流动分析仪测定葡萄酒中总二氧化硫具有很好的准确性和重复性,自动化程度高,测试速度快,适合于不同类型红酒分析,是一种高效、快速的分析手段。     

Properties and use of sulphur dioxide.

This work analyses comprehensively the mechanism of action of sulphur dioxide in the process of wine-making. The use of sulphur dioxide is still a necessity for the storage and preservation of white wines. Nevertheless, the study of its physico-chemical and antimicrobial properties can make possible a large reduction of doses used even for white wines.     

蒸馏法测定葡萄酒中二氧化硫的不确定度分析

对蒸馏法测定葡萄酒中二氧化硫的不确定度进行了评定。通过对实验中不确定度各分量的分析计算,测得葡萄酒中二氧化硫的含量为(0.0929±0.0028)g/L(k=2)。本实验不确定度具体由碘标准滴定溶液的标定及肉眼判断滴定终点所引起。