基于品质指标的苹果浊汁品种与产地差异性分析

以来自7?个不同主产区的21?个主栽品种,共41?份苹果鲜果为研究对象,对每个品种鲜榨浊汁的出汁率、浊度、果汁颜色、褐变度、透光率、可溶性固形物、可滴定酸、总酚、糖、有机酸、VC、矿物质、抗氧化性等品质指标进行测定。运用描述性分析、逐步线性判别分析进行数据处理。结果表明：不同品种或不同产地的苹果浊汁,品质差异较大。总体来看,a*值、原始浊度、褐变度、可滴定酸、葡萄糖、蔗糖、苹果酸等指标的变幅均较大,分别为94.07%、70.41%、42.86%、35.26%、42.02%、42.40%、37.69%。对于不同品种的苹果浊汁,由于褐变度、总酚、抗氧化性等色泽品质指标以及糖、酸等营养品质指标间具有较大差异,其分布呈现分散状态。其中新红星品种的褐变度、总酚含量、DPPH自由基清除率等品质指标普遍居高,色泽品质差异最显著。富士品种大部分样品的果糖、葡萄糖、蔗糖、苹果酸等指标含量较高,具有较好的营养品质。然而对于不同产地间的样品,其浊度、可滴定酸、可溶性固形物等加工品质指标具有较大差异,样品分布较为分散。河北省样品的出汁率、原始浊度、可滴定酸等指标普遍较低,加工品质较差。来自山东省不同品种苹果浊汁的样品以及来自不同产地富士苹果浊汁的样品间均具有较大差异,并且分别获得了77.8%和72.7%的判别准确率。以上结果表明,不同产地、不同品种苹果原料制得的苹果浊汁存在较大差异,通过对其品质指标进行差异性分析,可为上游育种与种植产业结构调整提供数据基础;通过判别模型的建立实现品种与产地的识别与预测,可以指导企业对苹果原料进行制汁专用化筛选。     

NFC南果梨黄秋葵复合汁配方优化及杀菌方式对其品质的影响

以南果梨和黄秋葵为主要原料制作南果梨黄秋葵非浓缩还原汁（Not From Concentrate,NFC）,以感官评分为指标通过单因素和正交试验优化NFC南果梨黄秋葵复合汁配方,并研究巴氏、微波和超高压三种杀菌方式对复合汁杀菌效果、理化性质和风味的影响。结果表明:南果梨汁与黄秋葵以质量比15:1榨汁复合后,按南果梨和黄秋葵复合汁含量93.98%、白砂糖添加量6%和柠檬酸添加量0.02%进行复配,感官评分最高为89.4。三种杀菌方式处理后复合汁均达到商业无菌状态。与未杀菌样品相比,微波和巴氏杀菌复合汁总酸含量和自由基清除率发生显著下降（P<0.05）,pH、非酶褐变指数、苦味和涩味显著上升(P<0.05);微波和超高压处理后复合汁可溶性固形物含量显著上升（P<0.05）;超高压处理后复合汁总酸含量、苦味和涩味显著下降（P<0.05）。与其他两种杀菌方式相比,超高压杀菌的复合汁?E变化最小,为4.26±0.12,DPPH自由基和羟自由基清除率最大分别为78.79%±0.37%和68.84%±0.42%,较好保持了复合汁色泽和抗氧化性。     

莲藕复合果蔬汁配比优化方法探讨

运用Mixture D-optimal设计,以感官评价为响应值,研究了以莲藕、梨、冬瓜和苹果4种原汁的不同配比对复合果蔬汁风味等感官品质的影响,确定了莲藕复合果蔬汁最优配方为:莲藕原汁49%、梨原汁21%、冬瓜原汁10%和苹果原汁20%,成品的糖酸比为20.34。     

鸭梨汁加工过程中褐变的控制及澄清方法研究

以鸭梨为原料,研究了不同护色列(维生素C、亚硫酸氢钠和柠檬酸)对梨汁褐变的影响。采用正交试验的方法,研究了果胶酶、单宁、PVP(聚乙吡咯烷酮)对果汁得率和澄清效果的影响。结果表明:鸭梨汁加工过程中加入0.035％的抗坏血酸,0.03％的亚硫酸氢钠和0.01％的柠檬酸抑制褐变效果较好。为了得到透光率较高的果汁,并考虑到果汁得率和尽可能降低成本,采用0.03％果胶酶、0.03％单宁、0.03％PVP处理较为适宜     

Influence of PET and PET/PEN Blend Packaging on Ascorbic Acid and Color in Juices Exposed to Fluorescent and UV Light

ABSTRACT: Apple and orange juices packed in polyester bottles were stored in dark, intense fluorescent (1500 lux), and UV light conditions in temperature-controlled (22 °C) chambers and monitored more than 7 mo for ascorbic acid content and color changes. Polyester beverage bottles were made of polyethylene terephthalate (PET), or PET blended with 0.25%, 1%, and 4% polyethylene naphthalate (PEN). The cut-off wavelength ranged from 322 nm for PET to 373 nm for the 4% PEN/PET blend. Spectral irradiance, visible light intensity, and light distribution were evaluated in the light chambers and compared with supermarket display lighting and outdoor daylight conditions. Only the UV chamber and sunlight showed significant irradiance at wavelengths below 400 nm. Ascorbic acid (AA) degradation and concurrent color changes occurred in both juices during storage in all 3 lighting conditions and in all 4 bottle types. Zero-order reaction kinetics described the AA degradation rate for all treatments. Apple juice stored in UV had a significantly higher ( P < 0.05) AA degradation rate than juice stored in the dark or in fluorescent light. Under UV conditions, apple juice in PET/ PEN bottles had a lower AA degradation rate than the juice in PET bottles. AA degradation in orange juice was less affected by UV exposure than in apple juice. Both juices darkened over time when stored in dark and fluorescent conditions, whereas UV exposure caused some initial bleaching of color before darkening. The bleaching effect was reduced in apple juice stored in the PET/PEN bottles.     

QUALITY CHANGES DURING STORAGE IN KOREAN CLEAR PEAR JUICES CONCENTRATED BY THREE METHODS

Pears of Shingo variety were coarsely ground, and subjected to heat treatment by HTST (high temperature short time) and pectinase treatment to produce a cloudy pear juice. The pear juice was then treated with Viscozyme, gelatin and bentonite, and filtered through an ultrafiltration membrane to produce a clear pear juice. The clear pear juice was concentrated to 3 to 5 fold by vacuum evaporation, freeze concentration, and reverse osmosis methods. The concentrates were diluted to 10° Brix and stored at 4C for 15 days. The single strength juice was evaluated for color, turbidity, heat stability, and sensory preference at 5 day intervals during storage. The pear juice concentrated by the three methods showed only small differences in quality. While the clear pear juice with added ascorbic acid had no quality changes at 4C after 15 days' storage, that without the addition of ascorbic acid resulted in some deterioration in browning, turbidity and heat stability after 10 days' storage. There were small, but significant flavor differences among clear pear juices concentrated by evaporation, freeze concentration and reverse osmosis.     

Singlet Oxygen Quenching Activities of Various Fruit and Vegetable Juices and Protective Effects of Apple and Pear Juices against Hematolysis and Protein Oxidation Induced by Methylene Blue Photosensitization

ABSTRACT:  Effects of various fruit and vegetable juices on rubrene oxidation induced by a chemical source of singlet oxygen in a microemulsion system have been studied. The singlet oxygen quenching activities of fruit and vegetable juices were greatly different with different juices. The apple and pear juices exhibited the highest antioxidative activity among the tested juices in singlet oxygen–induced rubrene oxidation, showing 56.69% and 59.34% inhibition, respectively. The grape, kumquat, red cabbage, and spinach juices also showed relatively strong antioxidative activity against singlet oxygen–induced rubrene oxidation. Lemon juice showed the least activity, resulting in 0.63% inhibition of rubrene oxidation. The singlet oxygen quenching activities of 1 mL of apple and pear juices were equivalent to 33.97 and 34.64 mg ascorbate, respectively. Singlet oxygen quenching activities of juices had very low correlation with both ABTS radical scavenging activity ( R ²= 0.11) and total phenolic contents ( R ² < 0.1). However, a high correlation ( R ²= 0.66) was found between the ABTS radical scavenging activities and total phenolic contents of juices. The apple and pear juices also significantly inhibited both erythrocyte lysis and protein oxidation induced by fluorescence light illumination in the presence of methylene blue. Electron spin resonance (ESR) spectroscopy data showed that the protective activities of these juices against biological damages induced by photodynamic ways were, to at least some extent, due to their singlet oxygen quenching abilities. This represents first report on the singlet oxygen quenching activities of the apple and pear juices, and their protective activities against photodynamically induced biological damages.     

Removal of phenolic compounds in pomegranate juices using ultrafiltration and laccase-ultrafiltration combinations

Phenolic compounds of fruit juices are responsible for haze and sediment formation as well as for color, bitterness and astringency. The influence of ultrafiltration (UF) and laccase-UF combination was investigated on phenolic contents of pomegranate juices and on filtration output. Laccase-treated and then ultrafiltered pomegranate juices have shown a rapid increase in their color, when compared to only ultrafiltered (control) samples. Kinetic parameters of laccase were also determined. During the oxidation period, the changes occurring in pomegranate juices were estimated from phenolic contents, color and anthocyanin measurements. Results have shown that laccase oxidation produced a significant decrease in phenolic content of pomegranate juices while juice color the increased. However, in recent literatures, the possibility to remove polyphenols in apple juices was reported. We decided in this study that laccase treatment can not be applied due to the loss of natural red color and unwanted dark brownish color formation in pomegranate juice.     

Removal of phenolic compounds in pomegranate juices using ultrafiltration and laccase‐ultrafiltration combinations

Phenolic compounds of fruit juices are responsible for haze and sediment formation as well as for color, bitterness and astringency. The influence of ultrafiltration (UF) and laccase‐UF combination was investigated on phenolic contents of pomegranate juices and on filtration output. Laccase‐treated and then ultrafiltered pomegranate juices have shown a rapid increase in their color, when compared to only ultrafiltered (control) samples. Kinetic parameters of laccase were also determined. During the oxidation period, the changes occurring in pomegranate juices were estimated from phenolic contents, color and anthocyanin measurements. Results have shown that laccase oxidation produced a significant decrease in phenolic content of pomegranate juices while juice color the increased. However, in recent literatures, the possibility to remove polyphenols in apple juices was reported. We decided in this study that laccase treatment can not be applied due to the loss of natural red color and unwanted dark brownish color formation in pomegranate juice.     

桑椹果汁加工技术研究

本研究对桑椹果汁有机酸HPLC分析,含柠檬酸为1.06％。单宁含量达206rag/100ml。新鲜榨取的果汁,室温下经过6 hr,乙醇和挥发酸(以醋酸计)含量开始变化,12 hr后分别为0.1％和0.2％,是原来的2倍和8倍,果汁出现明显的刺喉现象。桑椹果汁经冻藏解冻后,单宁含量减少了22％,涩味减轻。感官评定含原汁20％的桑椹果汁饮料,评价最高者为酸度0.3％、糖度13Brix的组合,所喜好的酸度范围较窄。高温和金属罐包装贮藏明显促进桑椹果汁花色苷的降解,单宁色变率(CDT％)相应提高。     

黑果腺肋花楸果汁产品品质分析与综合评价体系的建立

该研究以现有较高销量14款市售黑果腺肋花楸果汁类产品为试材,通过测定产品的色度、理化、酚类物质含量及抗氧化能力等共18项品质指标,采用主成分分析法,建立黑果腺肋花楸果汁产品品质分析与综合评价体系,并使用该体系对市售黑果腺肋花楸果汁产品进行评价。主成分分析结果显示：前4个主成分方差累计贡献率达到91.88,h°（0.56）、总酸（0.90）、糖酸比（0.54）、悬浮稳定性（0.48）、黄酮（0.82）、缩合单宁（0.82）、FRAP（0.57）、DPPH（0.70）在前四个主成分中载荷权数较大,是黑果腺肋花楸果汁类产品的特征评价指标。总体而言,浓缩口服液及100%果汁产品综合品质较优;ZH系列果汁饮料在其产品类别中综合品质较优。该研究通过建立黑果腺肋花楸果汁类食品品质分析与综合评价体系,为黑果腺肋花楸果汁类食品的开发利用提供数据基础与理论支撑,对于黑果腺肋花楸产业的健康发展具有重要意义。     

QUALITY AND STABILITY OF BLUEBERRY JUICE BLENDED WITH APPLE,GRAPE AND CRANBERRY JUICE1

Sensory quality and storage stability of blueberry juice blends were investigated with the goal of maintaining dominant blueberry flavor, aroma and color. Apple juice, Concord and Venus grape juices and cranberry juice cocktail were blended at 75, 50 and 25% with blueberry juice. As the percent of blueberry juice decreased, the intensity of blueberry‐related sensory attributes decreased. The 25% Concord and Venus blends were the only blends that resulted in blueberry flavor similar to the reference. Apple and cranberry juice cocktail blended with blueberry juice produced several blends with good flavor and aroma, but they were not readily characterized as blueberry juice. All blends at the 25% level produced blueberry color equal to or greater than the reference. The juice samples were evaluated initially and after three months of storage at 37C. After storage, all blends had decreased red color.     

Haze Development in Aerobically or Anaerobically Produced Clarified Apple Juices

Haze production in aerobically or anaerobically produced Red Delicious apple juice was assessed following heating, aeration, and protein addition. Stored aerobic juice produced haze in 6 wk, but anaerobic juice was haze-free unless oxygen was introduced. Phenolic material was incorporated into haze in both systems. HPLC (detection at 420 nm) of concentrated juice and addition of 100 mg/L BSA suggested the presence in both juices of ‘reactive’ material which could complex and precipitate during storage. Phenolic compounds, heating, and especially oxidation during processing (and storage) appear to be major determinants of ‘haze potential’ in clarified apple juice.     

茶多酚对新鲜原果汁保鲜效果的影响

将茶多酚添加到苹果汁、橙子汁和雪梨汁这三种常见果汁中,与山梨酸钾、苯甲酸钠比较研究其对新鲜原果汁的保鲜效果.结果表明,100mg/kg的茶多酚与500mg/kg的山梨酸钾防腐效果相当,对酵母菌、大肠杆菌和金黄色葡萄球菌均有明显抑制作用,能有效保持果汁原有风味并延长保鲜期7～10d.三种果汁中,茶多酚对苹果汁的保鲜效果最...     

Mass spectrometric evidence for the formation of pigmented polymers in red wine

The polymeric materials (wine tannin) were isolated from a three-year-old Pinot Noir using Toyopearl TSK HW 40-F size exclusion chromatography. The wine tannin was analysed by reversed-phase and gel permeation high performance liquid chromatography, UV-Vis spectrophotometry and mass spectrometry. Analysis by gel permeation chromatography indicated that the isolate was in large part polymeric, and also indicated the presence of pigmented material monitored at a wavelength of 520 nm. Acid-catalysis in the presence of phloroglucinol indicated that the wine tannin contained 45% w/w known proanthocyanidin material. The wine tannins gave a complicated mass spectrum featuring a large number of intense signals derived from proanthocyanidins and, to a much lesser extent, a series of ions corresponding to masses consistent with direct condensation products of an anthocyanin with proanthocyanidins. The degree of polymerisation by mass spectrometry was detected to be as high as an octamer composed of an anthocyanin combined with a proanthocyanidin heptamer. Based upon current evidence, the anthocyanin was proposed to be bound from the C-6/8 or C-4 positions of the anthocyanin to the respective electrophilic or nucleophilic centre of the proanthocyanidins. Only the species with the C-6/8 position of the anthocyanin linked with the proanthocyanidins seemed to be pigmented. Under acid-catalysed conditions, an increase in malvidin-3-glucoside was observed, suggesting that the non-pigmented form is possibly converted to the pigmented flavylium form. This is the first mass spectrometric evidence confirming the existence of pigmented polymers with an extension to octamers in wine.     

金刺梨原汁脱涩及其与梨-南瓜复配果蔬汁的研制

目的:解决金刺梨原汁口感酸涩,开发口感良好、酸甜适口且稳定性高的金刺梨复配果蔬汁。方法:首先采用明胶吸附或β-环糊精包埋法进行原汁脱涩处理,其次拟采用鲜榨梨汁和南瓜浆进行复配,并进行巴氏杀菌条件优化。结果:加入0.5%明胶可使金刺梨原汁中单宁脱除率达到63.00%。根据感官评价结果和基本理化指标,确定复配果蔬汁的优化配比为金刺梨汁:梨汁:南瓜浆体积比为34:40:26;在85 ℃下处理3 min能够使复配汁中细菌总数降至1.38 lg CFU/mL,酵母和霉菌未检出（<1 CFU/mL）;其可溶性固形物含量、总酸含量分别下降了2.33%和5.98%,超氧化物歧化酶（SOD）保存率为67.8%,还原型维生素C（V_C）和总V_C的保留率分别为78.72%和80.30%;但热处理后复配果汁发生了一定程度褐变。结论:通过对金刺梨原汁进行脱涩及果蔬汁复配得到酸甜适度的金刺梨复配果蔬汁,可为金刺梨的深加工提供技术参考。     

Maturity and ripening effects on chemical and sensory properties of apple juice

The effects of harvest maturity and ripening on the chemical composition and sensory characteristics of ‘McIntosh’ and ‘Spartan’ apple juice were evaluated. Juice was extracted from fruit harvested at seven weekly intervals beginning 3–4 weeks before commercial harvest and from fruit held in air storage (1°C) for 1 to 3 months. Internal ethylene concentration and starch index were used as maturity indices. Principal component analysis of juice data (pH. titratable acidity, organic acids, soluble solids, sugars, phenols, turbidity, and Hunterlab colour) showed a distinctive maturity effect on the characteristics of juice extracted from fruit immediately after harvest or after storage. Triangle testing showed aroma and flavour differences in both ‘McIntosh’ and ‘Spartan’ to be first discernable when ethylene was first detected (internal ethylene concentration ≥ 0.1 μl litre^?1) and starch hydrolysis evident (starch index 3.0–5.0 for ‘McIntosh’, 1.5–3.0 for ‘Spartan’), or after 2–3 months of air storage. Sensory profiling of fruity aroma, total aroma, fruit flavour by mouth, sweetness, and sourness in the juices showed increased fruitiness and sweetness and decreased sourness with advancing maturity.     

适宜‘法国野’葡萄的葡萄酒生产类型探究

为挖掘云南地方酿酒葡萄品种‘法国野’的酿酒潜力,筛选适合该品种的葡萄酒生产类型和基本工艺。采用4种工艺酿制2个类型葡萄酒:浸渍发酵法(maceration-fermentation,MF)酿制干红葡萄酒、冷浸渍+放血法(cold pre-fermentation maceration&saignée,CMS)酿制桃红葡萄酒、冷浸渍+放血+浸渍发酵法(cold pre-fermentation maceration,saignée and maceration-fermentation,CMS-MF)酿制干红葡萄酒,直接压榨法(direct press,DP)酿制桃红葡萄酒,其中2款干红葡萄酒均进行苹果酸-乳酸发酵(malolactic fermentation,MLF)。陈酿3个月后,对4款葡萄酒进行理化指标分析和感官评价。结果表明:与DP和MF相比,CMS和CMS-MF可分别显著提高桃红和干红葡萄酒的单宁、花色苷、总浸出物含量及色度;且CMS和DP桃红葡萄酒的香气、口感和总评得分均显著高于MF和CMS-MF干红葡萄酒,但同类型葡萄酒间的感官质量并无显著差异(P <0.0...     

乳酸菌发酵对梨汁的护色作用

梨汁在加工过程中极易褐变,乳酸菌发酵能有效保护梨汁的色泽。本研究测定梨汁发酵及储藏过程中色泽、多酚氧化酶活性、酚类物质、抗坏血酸含量等指标的变化,并与未发酵梨汁和添加柠檬酸的调酸梨汁对比,探索乳酸菌发酵对果蔬汁的护色机理。30天储藏期内,未发酵梨汁褐变指数从0.073变化至0.310,显著高于发酵梨汁(0.134);乳酸菌发酵作用有效抑制了多酚氧化酶的活性,使得发酵梨汁中的酚类物质的保存率(43%)显著高于未发酵梨汁(16%);发酵梨汁中抗坏血酸稳定性更高,保存率(85%)较未发酵梨汁高(50%),减少了非酶褐变。乳酸菌通过在梨汁中发酵产酸,抑制多酚氧化酶的活性,保存酚类、抗坏血酸等物质,从而保护梨汁色泽。     

Matrix dependent impact of sugar and ascorbic acid addition on color and anthocyanin stability of black carrot,elderberry and strawberry single strength and from concentrate juices upon thermal treatment

Heat stability of strawberry, elderberry and black carrot juices prepared from concentrate and fresh plant material was investigated at pH 3.5 by heating at 95 °C for 2 and 4 h, respectively. The impact of added saccharides (glucose, fructose, sucrose) and ascorbic acid on 5-hydroxymethylfurfural (HMF) formation, browning together with the stability of anthocyanins and their color properties were assessed using high performance liquid chromatography coupled to diode array detection (HPLC-DAD) and ultraviolet–visible (UV–Vis) spectrophotometry. Thermal degradation products of anthocyanins and saccharides were identified using liquid chromatography coupled to multistage mass spectrometry (LC–MSⁿ). Pigment stability and color changes depended on anthocyanin structure and juice matrix. Whereas a slight but insignificant stabilizing effect of added sugars and ascorbic acid was observed in juice prepared from black carrot concentrate, obvious color differences were detected in strawberry and elderberry juices when ascorbic acid was added. Manually squeezed juices from fresh plant material showed higher color stability compared to juices prepared from concentrate which might be due to the retention of polymeric matrix compounds in the former. The data presented may contribute to the development of advanced technological processes for the production of coloring foodstuff and food with improved color stability.