Effect of grape pomace extracts obtained from different grape varieties on microbial quality of beef patty

Grape pomace extracts were obtained from 5 different grape varieties grown in Turkey. The extracts were concentrated to obtain crude extracts; and incorporated into beef patties at 0% (Control), 1%, 2%, 5%, and 10% concentrations to test their antimicrobial effects in different storage periods (first, 12, 24, and 48 h). The numbers of microorganism were generally decreased by the extract concentration during the storage period. All the microorganisms tested were inhibited by the extract concentration of 10% in all the storage periods. Furthermore, the foodborne pathogens including Enterobacteriaceae and coliform bacteria, and the spoilage microorganisms including yeasts and moulds and lipolytic bacteria were also inhibited by 5% of Emir, Gamay, and Kalecik Karasi varieties in beef patties. Considering the results, the extracts of grape pomaces might be a good choice in the microbial shelf life extension of the food products as well as inhibiting the food pathogens as the case of beef patties. PRACTICAL APPLICATION: Grape pomace consists of seeds, skins, and stems, and an important by-product that is well known to be the rich source of phenolic compounds, both flavonoids and non-flavonoids. These substances have considerable beneficial effects on human health. The use of natural antimicrobial compounds, like plant extracts of herbs and spices for the preservation of foods has been very popular issue because of their antimicrobial activity. Therefore, grape pomace should be added into some food formulations to benefit from their protective effects. In this respect, this study reports the effect of addition of grape pomace extracts obtained from different grape varieties on microbial quality of beef patty. The results obtained in this study may be useful for food industry, which has recently tended to use natural antimicrobial sources in place of synthetic preservatives to prevent microbial spoilage.     

不同熟制度牛肉的品质变化研究

选用品质相同的澳洲优质牛里脊肉制作牛排,分别测定其在三成熟、五成熟及七成熟时的烹饪失水率、持水力、剪切力、TPA物性、p H、水分、蛋白质含量、脂肪含量、灰分等,并建立感官评定小组进行感官评价。结果表明,烹饪失水率和持水力受牛肉的熟制程度影响较大。在质构特性上,三成熟与五成熟牛肉无显著差异,与七成熟牛肉差异显著。在营养成分上,牛肉的粗脂肪与水分含量逐渐降低,蛋白质与灰分含量无显著变化。从三成熟到七成熟的牛肉p H逐渐增大,表明加热过程带有轻微的排酸作用。感官评分上,七成熟牛肉的得分最高,此时牛肉的风味能最大限度地体现出来,嫩度与肉质纤维均保持最佳。      

酿酒葡萄皮渣中多酚物质提取的研究

以酿酒后分离的葡萄皮渣为原料,对其多酚类物质的提取条件进行了研究。在单因素试验的基础上,以乙醇体积分数、料液比、浸提时间、浸提温度为影响因素,以葡萄皮多酚得率为评价指标,进行4因素3水平正交试验,确定出的最佳浸提条件为浸提剂为体积分数70%的乙醇,浸提温度80 ℃,浸提时间40 min,按1∶7（g∶mL）的料液比,浸提次数为3次,在此条件下,葡萄皮渣中多酚提取量为30.03 mg/g。     

葡萄皮渣酿造葡萄醋过程中化学成分动态变化分析

利用葡萄皮渣发酵的葡萄酒醪进行醋酸发酵酿造葡萄醋,并研究发酵过程中化学成分的动态变化。采用GC-MS、氨基酸分析仪和原子吸收光谱对发酵过程中化学成分动态变化进行分析。结果表明:葡萄酒醪和葡萄醋的香气成分的种类相似,主要为酯类和醇类（主要是琥珀酸单乙酯和苯乙醇）;葡萄酒醪与葡萄醋氨基酸的种类和含量都相差较大,葡萄酒醪有15种氨基酸,葡萄醋只有5种氨基酸;检测的8种金属元素在葡萄酒醪和葡萄醋中差异不大。      

酿酒葡萄皮渣红外干燥研究

对酿酒葡萄皮渣进行红外干燥研究,以期优化葡萄皮渣的干燥工艺,也为其它物料的红外处理干燥提供理论基础。实验对自然晒干、连续红外干燥、间歇红外干燥以及红外对流两步干燥进行研究,对每种干燥方法的干燥特征、灭菌效果以及干燥质量进行比较分析,并且对不同干燥处理的葡萄籽的超微结构进行观察。结果表明,连续红外干燥的干燥速率最高;除自然晒干和IR9min-CD55℃外,所有干燥方法均具有较好的灭菌效果;皮渣的总多酚和原花青素在所有干燥过程中都有一定损失,连续红外干燥对总多酚和原花青素具有较好的保护作用;红外干燥的葡萄籽的组织之间出现较多的孔隙,而自然晒干和对流干燥的葡萄籽组织间没有或有少量的孔隙。综上,连续红外干燥适合酿酒葡萄皮渣的干燥处理,具有高干燥品质。      

微波辅助提取葡萄皮渣中白藜芦醇的工艺研究

目的优化葡萄皮渣中白藜芦醇的微波辅助提取工艺。方法通过单因素试验,选择微波时间、料液比以及微波功率为自变量,白藜芦醇提取率为考察指标,采用正交试验设计分析研究各自变量对多糖提取率的影响。经极差与方差分析,从而获得最适的提取工艺条件。结果在微波提取时间70 s、料液比1:20(m:V)、微波作用功率为600 W的条件下获得白藜芦醇提取率为0.284%,相比有机溶剂乙醇提取法的提取率增加了42%。结论本研究可为葡萄皮渣的再利用与开发提供参考。     

Antibacterial activities and total phenolic contents of grape pomace extracts

The aim of this study was to determine the total phenolic contents and antibacterial effects of grape pomace extracts (cultivars Emir and Kalecik karasi) against 14 bacteria, and the effects of the extracts on the growth and survival of two of the bacteria during storage. The total phenolic contents of grape pomace of Emir and Kalecik karasi cultivars extracted with acetone/water/acetic acid (90:9.5:0.5) were 68.77 and 96.25 mg GAE g^?1, respectively. The agar well diffusion method was used to test the antibacterial activity of the extracts at 1, 2.5, 5, 10 and 20% (w/v) concentrations in methanol on spoilage and pathogenic bacteria including Aeromonas hydrophila, Bacillus cereus, Enterobacter aerogenes, Enterococcus faecalis, Escherichia coli, Escherichia coli O157:H7. Mycobacterium smegmatis, Proteus vulgaris, Pseudomonas aeruginosa, Pseudomonas fluorescens, Salmonella enteritidis, Salmonella typhimurium, Staphylococcus aureus and Yersinia enterocolitica. All the bacteria tested were inhibited by extract concentrations of 2.5, 5, 10 and 20%, except for Y enterocolitica which was not inhibited by the 2.5% concentration. However, pomace extracts at 1% concentration had no antibacterial activity against some of the bacteria. According to the agar well diffusion method, E coli O157:H7 was the most sensitive of the bacteria. Generally, using the serial dilution method, while the extracts at 0.5% concentration had bacteriostatic activities on E coli O157:H7 and S aureus, the extracts appeared to have bactericidal effects at 1 and 2.5% concentrations. In accordance with this method, S aureus was more sensitive than E coli O157:H7 to the extracts. Copyright © 2004 Society of Chemical Industry     

Evaluation of the sensory and physical properties of meat and fish derivatives containing grape pomace powders

The wine industry produces tons of pomace that, in a circular economy model, should be valorised. The phenols fraction of grape pomace represents a source of food colorants, but also of natural food preservatives. Furthermore, the pomace contains dietary fibre, unsaturated lipids, antioxidants and minerals that have been recognised as wholesome and technologically useful. The main drawback of using grape pomace is represented by its chemical and microbiological instability. Different authors proposed strategies to overcome these limitations, and different approaches for the use of grape pomace as an ingredient have been described. Here, we sum up the chemical and microbiological solutions for the stabilisation of grape pomace, describing the approaches used to transform this waste in a functional ingredient, and comparing the physiochemical characteristics of the resulting products. We further describe the studies concerning sensory aspects of the products by enriching animal fleshes with different pomace powder preparations.     

Wine grape pomace as antioxidant dietary fibre for enhancing nutritional value and improving storability of yogurt and salad dressing

Wine grape pomace (WGP) as a source of antioxidant dietary fibre (ADF) was fortified in yogurt (Y), Italian (I) and Thousand Island (T) salad dressings. During the 3 weeks of storage at 4 °C, viscosity and pH of WGP-Y increased and decreased, respectively, but syneresis and lactic acid percentage of WGP-Y and pH of WGP-I and WGP-T were stable. Adding WGP resulted in 35–65% reduction of peroxide values in all samples. Dried whole pomace powder (WP) fortified products had dietary fibre content of 0.94–3.6% (w/w product), mainly insoluble fractions. Total phenolic content and DPPH radical scavenging activity were 958–1340 mg GAE/kg product and 710–936 mg AAE/kg product, respectively. The highest ADF was obtained in 3% WP-Y, 1% WP-I and 2% WP-T, while 1% WP-Y, 0.5% WP-I and 1% WP-T were mostly liked by consumers based on the sensory study. Study demonstrated that WGP may be used as a functional food ingredient for promoting human health and extending shelf-life of food products.     

Production of white wine by Saccharomyces cerevisiae immobilized on grape pomace

White wine was produced with Saccharomyces cerevisiae cells immobilized on grape pomace, by natural adsorption. The support, the main solid waste from the wine industry, consisted of the skins, seeds and stems. Immobilization was tested using different media, namely complex culture medium, raw grape must and diluted grape must. Grape pomace was revealed to be an appropriate support for yeast cell immobilization. Moreover, grape must was shown to be the most suitable medium as immobilized cells became adapted to the conditions in the subsequent alcoholic fermentation in the wine‐making process. The wines produced, either with immobilized cells or with free cells, were subjected to chemical analysis by HPLC (ethanol, glycerol, sugars and organic acids) and by gas chromatography (major and minor volatile compounds); additionally, colour (CIELab) and sensory analysis were performed. The use of immobilized systems to conduct alcoholic fermentation in white wine production proved to be a more rapid and a more efficient process, especially when large amounts of SO₂ were present in the must. Furthermore, the final wines obtained with immobilized cells demonstrated improved sensory properties related to the larger amounts of ethanol and volatile compounds produced. The more intense colour of these wines could be a drawback, which could be hindered by the reutilization of the biocatalyst in successive fermentations. Copyright © 2012 The Institute of Brewing & Distilling     

压榨对酿酒葡萄皮渣酚类物质提取及抗氧化活性的影响

酿酒葡萄皮渣（皮和籽）生物活性物质含量丰富,具有很高的再加工利用价值。对鲜葡萄皮渣进行压榨处理后再干燥,研究压榨对皮渣的酚类物质提取及抗氧化活性的影响。结果表明：压榨处理可以快速降低葡萄皮渣水分含量,缩短干燥时间、提高可溶性膳食纤维提取率。压榨葡萄皮总酚、原花青素的提取量均有所增加,其含量分别为19.56 mg/g和22.64 mg/g。压榨葡萄皮的抗氧化能力高于未压榨葡萄皮,其DPPH、ABTS及羟自由基清除率分别为62.90%、70.18%和41.09%,铁氰化钾还原能力及金属离子螯合能力分别为0.23%和21.33%。压榨籽和皮籽混合物的酚类物质和抗氧化活性则明显降低。抗氧化活性与总酚、原花青素存在显著的相关关系（P＜0.01）。     

发酵法活化葡萄皮渣膳食纤维工艺的研究

以葡萄酒厂的副产物-葡萄皮渣为原料,采用嗜热链球菌和保加利亚乳杆菌混合发酵技术活化其中的膳食纤维,提高了葡萄皮渣中可溶性膳食纤维的含量。经正交试验得到乳酸菌发酵活化葡萄皮渣膳食纤维的最佳反应条件为：液料比10：1（v／w）,菌种比1：1（v／v）,发酵温度42℃,发酵时间12h,接种量10％,产品SDF含量为19．54％（干基）,较原料中SDF提高3．6倍。     

葡萄皮渣多酚提取及其对五种食源性致病菌的抑制作用

以葡萄皮渣为原料,采用乙醇溶液对葡萄皮渣中的多酚类物质进行浸提,用Folin-Ciocalteu法测定多酚含量,通过单因素及正交试验得出浸提的最佳工艺条件为：乙醇体积分数45%,浸提温度48 ℃,浸提时间8 h,料液比1∶15(g∶mL),多酚得率为：16.48 mg/g。采用滤纸片法进行葡萄皮渣多酚的抑菌试验,发现其对金黄色葡萄球菌(Staphylococcus aureus)、志贺氏菌(Shigella)、单增李斯特菌(Listeria monocytogenes)、沙门氏菌(Salmonella)、大肠杆菌(Escherichia coli)都有一定的抑菌作用,其中对金黄色葡萄球菌和沙门氏菌的抑制效果最好。     

葡萄渣多酚的分布、生物活性及其在食品中的 应用研究进展

许多水果在加工过程中会产生大量的副产物,如葡萄酒酿造过程中产生的葡萄果渣(grape pomace,GP),由于其中含有丰富的生物活性物质,如多酚、膳食纤维、有机酸和不饱和脂肪酸等,已成为医药、化妆品和食品工业提取植物活性物质的廉价来源。尤其是酚类化合物受到越来越多的关注,葡萄渣中的酚类化合物是一类次生代谢产物,主要包括类黄酮、花青素和白藜芦醇等,很多研究已经证实这些酚类化合物具有抗氧化、抗菌、抗病毒、抗炎和抗癌等生物活性,因此,如何从葡萄渣中提取多酚化合物并将其开发成功能性食品配料,成为越来越多的企业和学者的关注。在此本文对GP多酚的组成分布、生物活性、在食品中的稳定性及其应用等进行了较全面的总结,旨在为葡萄渣多酚功能性食品的开发提供参考。     

White grape pomace as a source of dietary fibre and polyphenols and its effect on physical and nutraceutical characteristics of wheat biscuits

BACKGROUND: Grapes are one of the world's staple fruit crops, with about 80% of the yield being utilised for winemaking. Since grape by‐products still contain large amounts of secondary metabolites, uses other than as fertilisers might be appropriate. In this study, white grape pomace (WGP) was incorporated in wheat flour at levels of 10, 20 and 30% (w/w) to investigate its influence on rheological, nutraceutical, physical and sensory properties. RESULTS: Farinograph characteristics of dough with different levels of WGP showed a decrease in water absorption from 56.4% (0% WGP) to 45.9% (30% WGP). Addition of WGP reduced hardness and caused a deterioration in brightness and yellowness of all enriched samples. The smallest addition of WGP (10%) caused an approximately 88% increase in total dietary fibre content as compared with the control. The content of phenolic compounds increased from 0.11 mg g^?1 with 0% WGP to 1.07 mg g^?1 with 30% WGP. The most stable phenols were as follows: γ‐resorcylic acid < gallic acid < tyrosol < catechin < isovanilic acid. An assay of radical‐scavenging activity showed that WGP addition greatly enhanced the antioxidant properties of biscuits. Acceptable biscuits were obtained when incorporating 10% WGP. CONCLUSION: WGP might be utilised for the novel formulation of biscuits as an alternative source of dietary fibre and phenols. Copyright © 2012 Society of Chemical Industry     

Functional components of grape pomace: their composition,biological properties and potential applications

The roles of functional foods on human health have been realised by more and more researchers, food producers and consumers. Functional food ingredients from both plant and animal sources such as dietary fibre, soy protein isolate, whey protein isolate and omega 3 fatty acid have been widely used in functional food product development. Many fruit processing by‐products such as grape, apple and orange peels are rich in bioactive phytochemicals, dietary fibre and unsaturated fatty acids, hence have potential to serve as functional food ingredients. In this review, we summarise recent advancement of research in grape pomace (GP), the residual of grapes after wine making. The polyphenol profile of GP and their biological, antioxidant and antimicrobial activities, the stability of GP polyphenols in food system, the interaction between GP polyphenol and other food ingredients, as well as the functionalities of grape seed oil and GP fibre are covered.