Characterisation of Pomegranate Juices from Ten Cultivars Grown in Turkey

Pomegranate juices obtained from ten pomegranate cultivars of Turkey were analysed for their sugars, organic acids and the other quality parameters including pH, total soluble solids, and titratable acidity. Statistically significant differences were determined among the cultivars for parameters analysed. Citric acid was the predominant acid of all the cultivars studied. Cultivar “Zivzik,” one of the most popular cultivar in Turkey, showed best scores for total soluble solids (16.9 ± 0.06 °Brix), glucose (84.18 ± 0.42 g/l) and fructose (83.34 ± 0.81 g/l). Pomegranate juices were classified into three groups according to principal component analysis and cluster analysis.     

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。     

Juice Extraction Process and Apple Cultivar Influences on Juice Properties

Effects of several processing methods (oxidative, nonoxidative, diffusion extraction, enzyme liquefaction) on varietal apple juice character was examined. Analytical evaluations included titratable acidity, soluble solids, pH, phenol, suspended solids, turbidity, Hunterlab color, organic acids and sugars and showed definite extraction process and cultivar differences. Sensory evaluation identified eight attributes, color, clarity, fruity aroma, oxidized, fruity flavor, sweet, sour, astringent, as significant factors in characterizing differences among the juices. Canonical discriminant analyses (CDA) of analytical data showed correct allocation of all juices to both process type and variety. CDA of sensory data, revealed a significant separation of processes but not all cultivars.     

Effect of storage conditions on the chemical attributes of Ogbomoso mango juice

Mango juices were extracted from Ogbomoso variety using the method of Brekke et al. (1972). Mango juices were packaged in polyethylene films, polyethylene tetraphthalate (PET or plastic) bottles and transparent glass bottles and stored at 6 °C, 26 °C and 34 °C. Percentage ascorbic acid loss, browning index, titratable acidity, pH and soluble solids were evaluated at 2-week intervals for 8 weeks. Percentage ascorbic acid loss, non-enzymatic browning and titratable acidity increased with storage time in all packaging materials. However, pH decreased with storage time and soluble solids remained constant. Higher percentage ascorbic acid loss, browning index and titratable acidity occurred in juices packaged in polyethylene film, than in PET and glass bottles. Percentage ascorbic acid, browning index and pH increased with increased storage temperature. However, titratable acidity decreased with increased storage temperature and soluble solids remained constant throughout the period of storage.     

Degradation of quality attributes of sweetened Julie and Ogbomoso mango juices during storage

Changes in the quality attributes of sweetened Julie and Ogbomoso mango juices were investigated. Sweetened mango juices were processed, bottled and stored at 25 °C for 12 weeks. The titratable acidity, pH, total solids, ash, soluble solids and ascorbic acid contents were evaluated immediately after processing and subsequently at 2-week intervals. The L*, a* and b* (HunterLab) parameters were determined to evaluate colour changes due to non-enzymatic browning.Generally, the quality attributes of the sweetened mango juices decreased during storage. The titratable acidity, pH, total solids, ash, soluble solids and ascorbic acid contents decreased during storage. After 12 weeks of storage, the percentage ascorbic acid loss of sweetened Julie and Ogbomoso mango juices was 16.25 and 16.67%, respectively. Browning index, chroma and b* values increased during storage. Colour changes in sweetened mango juices were mainly due to b* value and chroma.     

Effects of Chitosan on Yield and Compositional Data of Carrot and Apple Juice

Effects of chitosans on yield, titratable acidity, pH, soluble solids, and color of carrot and apple juice were evaluated. Carrots (Lange Rote Stumpfe) and apples (Golden Delicious) were treated with chitosan solutions (in 2% ascorbic acid) of two different concentrations and viscosities at 25°C between 0 and 120 min. The juices were obtained with a laboratory cage press following a standard program during 20 min. Treatments with chitosan produced no effect on juice yield but pH values and soluble solids were affected. Also chitosan treatment resulted in significant (P < 0.05) reduction of titratable acidity and color index. Reduction of β-carotene in carrot juice was also achieved and correlated with color index.     

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.     

Sugar composition of apple juices

Fifty-one samples from 12 geographic growing regions of Turkey and 3 varieties common for production of apple juice concentrate were processed to apple juice and analysed for their sugar composition. Enzymatic analyses was used to determine soluble sugars of apple juice. Glucose, fructose, sucrose, total sugar concentrations (g/l) and total soluble solids (%) of apple juices were ranged, respectively, as follows: 9.30-32.2, 66.10-96.00, 8.5-55.10, 110.90-164.40, 11.80-18.60. Cultivar significantly influenced the content of all the sugar analysed. Significant differences in fructose and sucrose concentrations have also been found between some growing areas.     

Influence of addition of insoluble solids,different yeast strains and pectinesterase enzyme on the quality of apple wine

Rate of fermentation and physico‐chemical characteristics of apple wines, owing to the addition of different yeast strains, insoluble solids and pectinesterase enzyme, were examined. The highest rates of fermentation and ethanol production were found in the wine fermented by yeast strain UCD 505, while strain UCD 595 gave the smallest amount of methanol. The addition of insoluble solids to the apple juice significantly increased the levels of methanol, vitamin C, amyl alcohol, total volatiles, rate of fermentation, tannins, colour units, Mn and Zn. Addition of insoluble solids decreased pH, titrable acidity, ethanol, total sugars, total esters, and K, Mg, Ca, Cu and Fe content of the wine. Addition of pectinesterase enzyme significantly increased all the parameters examined except for pH, vitamin C, total esters, Mn and Mg content. Application of cluster analysis to the results of rate of fermentation, reducing sugars, volatile acidity and ethanol showed that the influence of the yeast strains was more than the influence of insoluble solids or pectinesterase enzyme addition. Consideration of more parameters showed that there was a clear interaction between the yeast strain, insoluble solids and the pectinesterase enzyme. Addition of insoluble solids to the must led to the production of some undesirable quality characteristics. In contrast, specific yeast strains and enzyme addition improved various physico‐chemical characteristics of the wine. Pre‐settled or clarified juice was preferred to produce a quality apple wine. Copyright © 2013 The Institute of Brewing & Distilling     

Changes in chemical composition of coconut (Cocos nucifera) water during maturation of the fruit

Changes in chemical composition of coconut (Cocos nucifera) water, including total and soluble solids, titratable acidity (as citric acid), turbidity, ash, lipids and sugars, were investigated in four varieties of coconuts at four stages of maturity of the fruit. The most significant change was observed in the volume of nut water, which increased during development from 233 to 504 ml, with the greatest quantity found at 9 months. Fat, protein, soluble solids, acidity and turbidity also increased steadily with maturity, while pH and ash showed variation throughout maturation. The interaction of variety and stage of maturity of the fruit appeared to have a significant effect on the chemical composition of the coconut water. Copyright © 2004 Society of Chemical Industry     

Effect of cultivar and fruit storage on basic composition of clear and cloudy pear juices

BackgroundPears due to low acidity are a suitable raw material for the production of multifruit nectars thus it is justified to determine the chemical composition and investigate the effect of cultivar and fruit maturity on juices quality.MethodsJuices from ‘Alexander Lucas’ and ‘Conference’ cultivars were produced after harvest and after 3 months of pears storage.ResultsAverage yield of clear juices was 76.4% for ‘Conference’ cultivar and 74.3% for ‘Alexander Lucas’. In the case of cloudy juices, the yield was lower by about 3%. Processing of ‘Conference’ cv. from stored fruit resulted in yield decrease compared to fruits after harvest; this was not in case of ‘Alexander Lucas’ in 2008, where juices produced from stored fruits were characterized by a higher yield compared to fresh fruit.Total solids content in clear juices was 125–135 g/L and 135–141 g/L for cloudy juices. ABTS^●+ and total phenolics analysis showed that cloudy juices were characterized by a higher antioxidant activity and phenolics content than the clear ones.ConclusionPear storage, on the contrary to apples, does not decrease their suitability for cloudy juice production. Cloudy juices as a rule have higher antioxidant activity than the clear ones.     

浓缩苹果汁加工中酶作用及贮藏稳定性研究

以红富士苹果浓缩汁为材料,采用单因素试验,研究果胶酶和α- 淀粉酶对还原糖、总酸、可溶性固形物等几个指标的影响,同时找出适合浓缩苹果汁澄清的果胶酶和α- 淀粉酶的酶用量、温度和时间。实验结果表明,在酶用量0.1%、温度50℃、时间1.5h 的条件下,浓缩苹果汁的澄清效果较明显。将加入果胶酶和α- 淀粉酶的浓缩苹果汁置于4℃和26℃条件下贮藏,测定其在贮藏过程中还原糖含量、总酸含量、pH 值和透光率等指标的变化。结果表明,在4 ℃贮藏条件下,随着贮藏时间的延长,还原糖含量、总酸含量、pH 值、透光率变化幅度较小,果汁营养成分保持较好,适宜贮藏。     

Effects of pulsed electric field treatment of apple mash on juice yield and quality attributes of apple juices

The influence of apple mash treatment with pulsed electric fields (PEF) on yield and quality attributes of the resulting cloudy juices were investigated. Apple juice was produced at laboratory scale (400 g apples per lot) by mash treatment with pulsed electric fields at three different field intensities (1, 3, 5 kV/cm, n = 30 pulses) and manual pressing at room temperature. The juices were compared with untreated control juices of the same mash and with a juice after pectolytic mash treatment. Relative to the control samples, juice yield increased with increasing field intensities. The overall composition as described by pH, total soluble solids, total acidity, density, contents of sugar, malic acid and pectin, respectively, as well as the nutritive value with respect to polyphenol contents and antioxidant capacities (TEAC, FRAP, DPPH) of the PEF-treated apple juices did not significantly differ from the controls.Industrial relevanceThis paper addresses the composition of apple juice after mash treatment applying pulsed electric fields and maceration enzymes, respectively. Since substantial equivalence of products derived from novel technologies, such as PEF, relative to their conventionally produced counterparts is required according to European food law, this aspect is of great relevance, especially for commercialisation of fruit juices based on PEF technology. Furthermore, the nutritional value of juices produced at different pulsed electric field activities is of relevance for their marketing.     

Flavor Characteristics of Irradiated Apple Cider During Storage: Effect of Packaging Materials and Sorbate Addition

ABSTRACT: Apple cider, with (0.1%) and without potassium sorbate, was packaged in 3 different materials to evaluate the effects of irradiation (2 kGy) and storage on flavor. Irradiated apple cider samples were compared with unirradiated samples stored in glass jars. Volatile flavor compounds, soluble solids, and titratable acidity were determined weekly throughout 3 wk of refrigerated storage. Oxygen permeability of the packaging materials was important in the retention of flavor during storage. Cider irradiated and stored in polystyrene containers or nylon-6 packaging materials (low oxygen permeability) had lower rates of loss of characteristic flavor compounds compared with unirradiated apple cider and cider irradiated and stored in low-density polyethylene (high oxygen permeability). The presence of sorbate, functioning as a yeast and mold inhibitor, reduced the rates of loss of the characteristic flavor compounds and the fermentation of sugars to acids. Principal component analysis resulted in several esters characteristic of apple flavor, soluble solids, and titratable acidity loading onto the 1st principal component (PC-1). Packaging material and sorbate treatment had the greatest effect on the compounds that loaded onto PC-1.     

COMPOSITIONAL ANALYSIS OF FOUR RED RASPBERRY CULTIVARS GROWN IN MAINE

The compositional characteristics (total soluble solids, pH, titratable acidity, moisture, pectin, reducing sugars, nonreducing sugars and total sugars) of four raspberry cultivars (‘Boyne’, ‘Festival’, ‘Killarney’ and ‘Prestige’) grown in Maine were evaluated during three consecutive years. Significant differences were found among these cultivars. In different growing seasons there were also significant effects on these characteristics in the same cultivar.     

CaCl_2对苹果酒酿造的影响

对以红富士苹果为原料 ,分别添加 0 3、0 4、0 5g/LCaCl2 的澄清苹果汁进行了研究。清汁中接种酿酒酵母Aw(Saccharomycescerevisiae ,Aw) ,于 2 0℃控温发酵 ,陈酿、澄清后进行理化、感官分析与风味物质测定。研究显示 ,添加CaCl2 显著地提高了果汁的澄清度、加快了果汁澄清速度。果汁处理时间低于 12h时 ,CaCl2 加量以 0 4g/L为宜 ;处理时间在 18～ 2 2h ,CaCl2 加量为 0 3～ 0 5g/L。经CaCl2 增加酸度 ( 1 49～ 1 5 7g/L)、降低 pH值 ( 0 19～ 0 2 4)、对酵母酒精发酵、发酵过程中滴定酸和 pH的变化趋势无显著影响。CaCl2 处理的果汁发酵的苹果酒滴定酸度高、残糖低 ,总浸出物低 ,酒精浓度与未处理苹果酒接近 ;口味纯正、爽口 ,色泽好 ,果香味突出。     

Physicochemical Characterization of Pure Persimmon Juice: Nutritional Quality and Food Acceptability

Technological process for production of non‐astringent persimmon (Diospyros kaki Thunb. cv. “Rojo Brillante”) juice was described. The degree of fruit ripening expressed as color index (CI) varied between 12.37 and 16.33. Persimmon juice was characterized by determining physicochemical quality parameters as yield, total soluble solids (TSS), pH, titratable acidity (TA), organic acids, and main sugars. A thermal treatment of 90 ºC for 10 s was effective in controlling naturally occurring microorganisms for at least 105 d of storage without significantly affecting production of soluble brown pigments (BPs) and 5‐hydroxymethyl furfural (5‐HMF), total phenolic compounds (TPC), antioxidant capacity and acceptability of juice by panelists. Storage time affected all and each of the above parameters, reducing BPs, TPC and antioxidant capacity but increasing 5‐HMF content. Refrigerated storage enhanced the acceptability of the juices. This information may be used by the juice industry as a starting point for production of pure persimmon juices.     

Removal of limonin bitterness by treatment of ion exchange and adsorbent resins

This study, the selective removal of limonin bitterness from Washington navel orange juice by batch adsorption to the Amberlite XAD-16HP and Dowex Optipore L285 was investigated and the determination of some compositional changes that occurred with orange juices debittering using adsorption resins were the primary focus. Amberlite XAD-16HP and Dowex Optipore L285 have been successfully used to reduce bitterness to acceptable levels in Washington navel orange juices. Amberlite XAD-16HP does not have any important negative effects on the quality characteristics of orange juices. However, Dowex Optipore L285 reduces the titratable acidity (TA) in the orange juices and so increases the content of soluble solids contents (SSC), pH value, and ratio accordingly.     

澳洲青苹加工品质测定及感官评价

对澳洲青苹的加工品质进行了测定,结果表明：澳洲青苹的硬度为8.18kg/cm2时,出汁率为75.92%,可溶性固形物含量为13.1°Bx,可滴定酸含量为0.8%,VC含量为87mg/kg。通过打分的方法对澳洲青苹进行了感官评价,综合各因素得出结论,澳洲青苹更适合加工浓缩苹果汁。     

基于电特性的苹果干燥品质检测

对苹果片进行60 ℃恒温干燥,选取不同干燥时间点测定其8 项理化指标和4 个电参数的变化情况。结果表 明：随干燥时间延长,苹果含水率、质量密度降低,褐变度增大;可溶性固形物质量分数下降的同时其可滴定酸质 量分数升高,固酸比减小,可溶性固形物质量分数在干燥120 min后基本保持不变;VC含量、硬度与干燥时间呈显 著线性负相关。随干燥时间的延长,苹果相对介电常数和胞外电阻率下降,胞内电阻率和损耗因数呈波浪式变化。 对理化指标与电参数间的差异显著性分析发现,胞内电阻率和损耗因数不能用于干燥过程中苹果品质变化的检测; 相对介电常数、胞外电阻率与硬度、固酸比、VC含量、褐变度、含水率和质量密度间的相关性较高,与可滴定 酸、可溶性固形物质量分数无明显相关性。据此,建立以相对介电常数和胞外电阻率为自变量,6 个生理指标为因 变量的线性方程,建立苹果电参数和理化指标间的关系,对快速评价其干燥加工过程中的品质变化具有指导意义。