Nondestructive Methods to Evaluate Maturity Level of Oranges

The maturity on the tree and the ripening during postharvest of 2 orange varieties ( Citrus sinensis , cvs. Lanelate and Valencia) were evaluated, using 3 methods: the ratio soluble solids/titratable acidity (Maturity Index); the firmness, by hand densimeter, and the skin color with a portable colorimeter. The values of Color Index (1000a*/L*b*) and firmness complement each other for defining the maturity of tree fruit. Color and Maturity Indices are not correlated with time or weight losses during storage (8 °C) or with shelf life (20 °C). Firmness and weight loss are significantly (P < 0.05) correlated with each other, and both of them independently of each other, with postharvest time.     

高效液相色谱法测定番茄酱中番茄红素含量及其与色度值的相关性

建立基于高效液相色谱法（high performance liquid chromatography, HPLC）的番茄酱中番茄红素异构体及总含量测定方法，并进行了方法学验证。同时，检测并分析了市售番茄制品中番茄红素顺反式异构体的分布情况，探讨了市售番茄制品的色度值与番茄红素含量之间的相关性，方法采用YMC-carotenoid（C₃₀，250 mm×4.6 mm，5 μm）色谱柱、以甲醇-甲基叔丁基醚作为流动相、流速1.3 mL/min进行梯度洗脱，在472 nm检测波长下进行检测，结果表明番茄红素在10~200 μg/mL范围内与峰面积线性关系良好（R2=0.9997），平均加标回收率在98.3%~99.6%之间，相对标准偏差在2.8%~4.5%之间，该方法简便、灵敏、准确，适用于番茄酱中总番茄红素的检测。相关性结果表明色度值a*、Chroma值与番茄红素有极显著的相关性（P<0.01），a*/b*、H°值与番茄红素含量有显著相关性（P<0.05），回归分析的最佳拟合结果为R2=0.689。     

Degradation kinetics of tomato juice quality parameters by ozonation

Tomato juice samples were ozonated with control variables of ozone concentration (1.6–7.8 %w/w) and treatment time (0–10 min). Effects of ozone processing variables on quality parameters of pH, ^oBrix, titratable acidity (TA), cloud value, non-enzymatic browning, colour values ( L *, a *, and b *) and ascorbic acid (AA) content were determined. No significant changes ( P  > 0.05) in pH, ^oBrix, TA, cloud value and Non enzymatic browning (NEB) ( P  ≤ 0.05) were found with ozonation. L *, a * and b * colour values were significantly affected by ozone concentration and treatment time. A significant reduction of AA (96 %) was observed at an ozone concentration of 7.8%w/w and a treatment time of 10 min. Results presented in this study indicate that visual colour and nutritional quality is significantly affected during ozone processing. Thus, the effects of ozonation on the nutritional properties of tomato juice should be considered by processors prior to its adoption as a preservation technique.     

Effects of electroplasmolysis treatment on chlorophyll and carotenoid extraction yield from spinach and tomato

In this study, the effects of electroplasmolysis on β-carotene, chlorophyll-a, chlorophyll-b and total chlorophyll contents of spinach extract and β-carotene and lycopene contents of tomatoes extracts were investigated. Three different voltage gradients (40, 60, 80 V/cm) and three different application periods (4, 8, 12 s) were used. The effects of water bath heating at different temperatures on the extraction yield of colorants were also studied. After pre-treatments, β-carotene, lycopene, chlorophyll-a, and chlorophyll-b extraction was performed. Total solid content, pH and titratable acidity of the spinach and tomato samples were also determined.In spinach, the highest extraction yield efficiency for β-carotene (19.7%) was obtained by water bath heating. The extraction yield efficiencies for chlorophyll-a, chlorophyll-b and total chlorophyll were 14.9%, 12.6% and 13.7% respectively, by the electroplasmolysis treatment at 60 V/cm for 8 s. In tomato, the highest increase in extraction yield efficiencies of β-carotene (139.1%) and lycopene (112.4%) was obtained by electroplasmolysis treatment at 80 V/cm for 4 s.     

Effect of Low Temperature Sonication on Orange Juice Quality Parameters using Response Surface Methodology

Freshly squeezed orange juice samples were sonicated at a constant frequency of 20 kHz for a range of processing temperatures (10–30 °C), amplitude levels (40–100%) and time (2–10 min) with pulse durations of 5 s on and 5 s off. Hunter colour values (L*, a* and b*), pH, ^oBrix, titratable acidity, cloud, non-enzymatic browning and ascorbic acid content were measured. Response surface methodology (RSM) based upon a three-factor, three-level Box–Behnken experimental design was used to determine the effect of independent variables. Under process conditions used in this study, no significant difference (p < 0.05) in pH, ^oBrix or titratable acidity was observed. Model predictions developed for Hunter colour values, cloud value, non-enzymatic browning and ascorbic acid content were closely correlated (R ² > 0.92) to experimental data. Box–Behnken design and RSM was demonstrated to be an effective technique to model the effect of sonication on juice quality while minimising the number of experiments required.     

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.     

Indices of sugar—acidity as ripeness criteria for winegrapes

Requirements for ripeness criteria of grapes for the making of dry table wine are considered, using measurements of sugar and acidity. The performance of indices was assessed by using averages of ‘optimum’ values of musts for top-quality dry-white and dry-red table wines obtained from a survey of prominent South Australian wine-makers. The defects of the ºBrix: titratable acidity ratio point to the need for an index which combines ºBrix and pH. ºBrix × pH leads to a large spread of pH values at extremes of ºBrix, while Brix:H+ gives an unrealistically narrow pH range. Brix × pH² appears to be an acceptable compromise.     

Physico-chemical,microbiological, and sensory characteristics of yogurt as affected by various ingredients

l-Glutamine, quercetin, slippery elm bark, marshmallow root, N-acetyl-d-glucosamine, licorice root, maitake mushrooms, and zinc orotate have been reported to help treat leaky gut. The purpose of this research was to explore the impact of these functional ingredients on the physico-chemical, microbiological, and sensory properties of yogurt. The milk from same source was equally divided into 9 pails and the 8 ingredients were randomly assigned to the 8 pails. The control had no ingredient. Milk was fermented to yogurt. The pH, titratable acidity, syneresis, viscosity, color (L*, a*, b*, C*, and h*), Streptococcus thermophilus counts, and Lactobacillus delbrueckii spp. bulgaricus counts of yogurts were determined on d 1, 7, 14, 21, 28, 35, and 42, whereas coliform counts, yeast and mold counts, and rheological characteristics were determined on d 1 and 42. The sensory study was performed on d 3 and particle size of the functional ingredients (powder form) was also determined. When compared with control, the incorporation of slippery elm bark into yogurts led to less syneresis. l-Glutamine increased pH and n′ values (relaxation exponent derived from G′) and lowered titratable acidity values. N-Acetyl-d-glucosamine incorporation resulted in higher n′ and lower titratable acidity values, whereas maitake mushroom led to lower n′ values. Incorporating quercetin increased the growth of L. bulgaricus. Adding maitake mushrooms increased the growth of S. thermophilus but lowered apparent viscosity values, whereas quercetin decreased its S. thermophilus counts. Quercetin decreased L* and a* values but increased b* values, and maitake mushroom increased a* values. Thixotropic behavior increased with the addition of licorice root and quercetin. Adding slippery elm bark, N-acetyl-d-glucosamine, licorice root, maitake mushrooms, and zinc orotate into yogurt did not affect the sensory properties, whereas yogurts with quercetin had the lowest sensory scores. Overall, most of these ingredients did not cause major changes to yogurt properties.     

Protection of vessel permeability by genistein against lipopolysaccharide induced acute inflammation in a chick embryo chorioallantoic membrane model

Effects of dip treatments on nutritional quality preservation during the shelf life of fresh-cut tomato (Licopersicum esculentum Mill.) cv. Eufrates were investigated. Fresh-cut tomatoes were dipped in solutions of 2% ascorbic acid, citric acid, and calcium lactate for 2 min, then stored at 4°C for 20 days. Color (L*, a*, and b*), firmness, °Brix, phenolics, ascorbic acid content, antioxidant activity (DPPH), and sugars were measured during storage. Pathogen development was monitored, and a sensory evaluation was performed. Ascorbic acid was better in maintaining firmness. No treatments significantly affected °Brix, color, or sugars. Ascorbic acid maintained a higher antioxidant capacity, phenolics, and ascorbic acid content, and was better at reducing bacterial growth, while citric acid treatment was better at prevention of yeast and molds proliferation. Fresh-cut tomatoes showed good quality after 10 days of shelf life, except for flavor with the calcium lactate treatment. Ascorbic acid treatment better preserved the general and nutritional quality parameters.     

Nondestructive and Rapid Assessment of Intact Tomato Freshness and Lycopene Content Based on a Miniaturized Raman Spectroscopic System and Colorimetry

Tomatoes and tomato-related products are associated with many health benefits and disease risk reduction. This work was to explore the use of a miniaturized Raman spectroscopic system for rapid and nondestructive quality assessment of intact tomatoes. Combined with colorimetry and spectrophotometry methods, surface color and lycopene content of intact tomatoes were measured as references. The ratio of two chromaticity indices a*/b* of tomato surface increased when their freshness declined; the correlation coefficient (r) of the second-order polynomial curve-fitting was 0.908. The freshness discriminant model developed on Raman spectra gave a correctness of 85.6 %. The quantitative models performed poorly for predicting lycopene content based on Raman spectra. From the results obtained, it can be concluded that the established miniaturized Raman spectroscopic system was feasible for assessing the freshness of intact tomatoes. However, it is difficult to predict the lycopene content accurately.     

Harvest parameters to optimise storage life of European plum 'Oullins Gage'

European plum ( Prunus domestica L.) cv. 'Oullins Gage' was harvested according to firmness on five harvest dates. Fruit was analysed at harvest and during storage for weight loss, firmness, total soluble solids (TSS), titratable acidity (TA) and skin colour before and after a 3-day shelf-life period at 20 °C. Significant differences were found among harvest dates in fruit mass, skin colour, firmness, TSS and TA. Fruit mass, TSS and colour b * increased, whereas firmness and TA decreased significantly during the harvesting period. Firmness parameter as a maximum maturity index and TSS:TA (or b * colour, a non-destructive measurement) as a minimum maturity index could be used to distinguish maturity at harvest. It is suggested that the best post-storage quality of 'Oullins Gage' plums would be obtained when fruit is harvested with TSS:TA >9 or b * colour >30, but with a firmness >20N to assure a long storage life.     

纸片型1-MCP处理对安溪油柿果实采后生理和贮藏品质的影响

研究了纸片型1-甲基环丙烯（1-methylcyclopropene,1-MCP）处理对安溪油柿果实采后生理和贮藏品质的影响。采后安溪油柿果实用1.35 μL/L的1-MCP处理12 h后,在（20±1）℃、相对湿度85%下贮藏。结果表明：与对照相比,1-MCP处理能有效降低采后安溪油柿果实呼吸强度;抑制果实表面色度a*值、b*值、C*值、L*值和色调角h的变化,抑制果皮叶绿素含量下降和类胡萝卜素含量上升,降低果实转红指数,并保持较好的果实外观色泽;此外,1-MCP处理能保持较高的果实硬度及可溶性固形物、可滴定酸、总糖、蔗糖、还原糖质量分数和VC、单宁含量,减少果实质量损失。因此认为,1.35 μL/L纸片型1-MCP处理可有效延缓采后安溪油柿果实后熟衰老、改善果实贮藏品质。     

初烤烟叶主脉不同区段色度及Fisher最优分割法分析

  目的  分析初烤烟叶主脉不同区段色度值的变化,为烟梗的差异化加工和分类使用提供参考依据。  方法  以云烟87 B3F、C3F初烤烟叶为试验对象,将每片烟叶中的主脉平均分成6段,采用色差计测定每个区段烟梗粉末的色度值L*（明度值）、a*（红度值）、b*（黄度值）和E（总色差值）,利用单因素方差分析和回归分析分别研究不同区段烟梗色度值的差异性及变化趋势,并通过Fisher最优分割法分析2种烟叶主脉最佳的分段比例。  结果  ① 同一烟叶主脉不同区段烟梗的色度值L*、a*、b*、E总体均存在显著差异;B3F和C3F烟叶主脉相同区段的色度值对比,L*值为C3F > B3F,a*、b*、E值为B3F > C3F。②从主脉基部到尖部,L*值呈先降低后升高的抛物线形变化趋势,a*、E值呈先升高后降低的抛物线形变化趋势,b*值呈逐渐升高的线性变化趋势。③从梗基到梗尖,B3F烟叶主脉最佳分段比例可分为1/6、3/6、1/6、1/6,C3F烟叶主脉最佳分段比例可分为4/6、1/6、1/6。  结论  烟叶主脉不同区段的色度存在较大差异和规律性变化趋势,叶基和叶中部分的烟梗更适宜作为制梗丝的原料。      

Influence of source and quality on the color characteristics of annatto dyes and formulations

Annatto dyes containing different strengths of bixin, norbixin and their formulations such as water-soluble liquid, and oil soluble liquid were measured for L*, a* and b* in a Hunter color meter and the Yellow (Y) and red (R) units in a Lovibond tintometer. Seed source and dye purity had a significant effect (P < 0.05) on the color characteristics L*, a*, b* and Y and R units of bixin/norbixin dyes and their formulations. These characteristics behaved independently when different dyes diluted to a common concentration of 50 mg bixin or norbixin/L. However, when individual bixin/norbixin dyes serially diluted L*, b* decreased and a* values increased with increase in concentration of bixin/norbixin. Similarly the increase in concentration of bixin/norbixin have shown decreasing trend on Y/R values due to increase in R-values in the tintometer. It has been observed that a* and R units generally increased with increase in concentration, and L* and b* values decreased and Y values are almost constant in both the bixin and norbixin dyes. However the b*/a* values showed lower values in bixin dyes and higher in norbixin dyes. Similarly R-values were higher in bixin dyes when compared to norbixin dyes.     

Physicochemical Changes in Seven Tomato (Lycopersicon esculentum) Cultivars During Ripening

Seven tomato cultivars were studied for compositional changes during ripening at green, breaker, turner, and ripe stages. Result indicated changes in total soluble solids (4.15 to 6.62 g/100 g), acidity (0.36 to 0.54 g/100 g), reducing sugars (0.76 to 4.04 g/100 g), total sugars (1.67 to 5.52 g/100 g), lycopene in skin (0.07 to 14.28 mg/100 g), and in pulp (0.04 to 6.73 mg/100 g) during ripening from green to red ripe stage. Cultivar UC-828 was found superior with respect to total soluble solids (6.62 g/100 g), reducing sugars (4.04 g/100 g), and total sugars (5.52 g/100 g) where as cultivar 8–2–1–2–5 was found superior with respect to lycopene in skin (14.28 mg/100 g) and in pulp (6.73 mg/100 g). Hunter color values showed a change from negative value of ‘a’ (greenness) to positive values (redness) where as ‘b’ decreased. The (b/a) and tan^?1 (b/a) showed a similar pattern of first increased and then decreased. The puncture resistance was decreased from 10.5 to 2.3 N indicating softening during ripening. Correlation studies showed that lycopene content best correlated with Hunter ‘a’ values during ripening (R² = 0.84 to 0.93). Intercultivar variation in physicochemical parameters at all stages of ripening revealed that Castle Rock was the best cultivar.     

Thermal Pasteurization Effects on Color of Red Grapefruit Juices

Changes in color due to thermal pasteurization of two cultivars of red grapefruit juice were studied. Juices were pasteurized at 91°C using a plate heat exchanger. Apparently, thermal pasteurization changed all three color parameters (CIE L*, a*, b*) in the juice, causing a slight color shift towards lighter and brighter. Thermal pasteurization especially affected CIE b* value and chroma in juice. The reflectance spectrum in the visible region (400 nm to 700 nm) clearly showed changes in spectral distribution of light reflected from juice after pasteurization. There were no changes (P>0.05) in major carotenoid pigments (β-carotene and lycopene) in the juices after pasteurization.     

蟠桃品种用于加工鲜榨汁的适宜性评价

为研究不同蟠桃品种的鲜榨汁加工适宜性,本实验对北京平谷地区的7 个蟠桃品种的理化与营养指标（pH值、总酚含量、抗坏血酸含量、蛋白质含量、可滴定酸含量、可溶性固形物含量（soluble solids content,SSC）、固酸比、果胶含量）和加工品质指标（单果质量、L*、a*、b*值、褐变度、出汁率、黏度）进行了测定,并从色泽、气味和风味三方面进行感官评价。通过相关性分析、主成分分析和聚类分析法筛选出了SSC、出汁率、果胶含量、a*值和蛋白质含量5 个核心品质评价指标。通过层次分析法得出：SSC和出汁率的权重值为0.32,果胶的权重值为0.18,a*值和蛋白质的权重值分别为0.11和0.07。对7 个蟠桃品种的鲜榨汁品质综合评价表明：瑞蟠21的鲜榨汁品质最好,其次为瑞蟠20、瑞蟠4和瑞蟠19,而巨蟠、瑞蟠2和瑞蟠3的鲜榨汁品质较差。     

Changes in pH, acids, sugars and other quality parameters during extended vine holding of ripe processing tomatoes

BACKGROUND: Two important quality attributes of processing tomatoes are pH and titratable acidity. These and other quality attributes can be affected by tomato fruit maturity and over‐maturity. We have determined the magnitude of these maturity effects in four processing tomato cultivars commonly grown in California. RESULTS: Allowing tomatoes to remain on the vine for up to 4 weeks after ripening resulted in an increase in fruit pH of between 0.01 and 0.02 unit per day for the four cultivars examined. The increase in pH was paralleled by a decrease in titratable acidity, due to a loss of citric acid. Glucose and fructose concentrations also declined with increasing maturity after ripening. Other quality parameters (color, lycopene, total pectin, pectin solubility, and Bostwick consistency) all showed little change. CONCLUSION: Vine holding of ripe fruit adversely affects quality, especially pH and titratable acidity. Recent problems with high tomato juice pH encountered by tomato processors in California could be the result of increased average fruit maturity at harvest. Copyright © 2011 Society of Chemical Industry     

蒙顶黄芽不同加工工序中色泽变化与品质相关性研究

研究不同加工工序制成的蒙顶黄芽干茶、汤色及叶底色泽,并进行色素成分检测及品质审评,分析干茶、汤色及叶底色泽L*a*b*值与各审评因子得分、色素含量、品质总分的相关性,为黄茶闷黄程度及色泽的评价提供一定的参考依据。以蒙顶黄芽加工过程中的茶样为试验材料,采用色彩色差计CR410测定干茶、汤色及叶底的L*a*b*值,再与干茶、汤色、叶底得分做显著性分析,与茶色素、叶绿素及品质总分做相关性分析。结果表明,干茶L*、a*、b*值与干茶色泽审评得分呈显著或极显著相关（P<0.05, P<0.01）,茶汤L*、a*、b*值与汤色审评得分均呈极显著相关（P<0.01）,其相关系数分别为?0.93、0.97、0.93,叶底L*、a*、b*值与叶底得分均呈极显著相关（P<0.01）,其相关系数分别为?0.96、0.97、0.98;干茶、汤色及叶底的L值与茶色素含量呈极显著负相关（P<0.01）,a*、b*值与茶色素含量呈极显著正相关（P<0.01）;干茶、汤色及叶底的L*值与叶绿素含量呈极显著正相关（P<0.01）,a*、b*值与叶绿素含量呈极显著负相关（P<0.01）。蒙顶黄芽感官品质与L*、a*、b*值及色素之间的相关性表现为:与干茶 L *值、汤色L *值、叶底L *值、叶绿素a*、叶绿素b*含量均呈极显著负相关（P<0.01）,与干茶a*b*值、汤色a*b*值、叶底 a*b*值及茶色素含量均呈显著或极显著正相关（P<0.05, P<0.01）,除干茶a*值外,相关系数均在0.80以上。本试验表明,就各审评因子及品质总分而言,采用色泽Lab值测定方法可为黄茶色泽与品质相关性研究提供一定的理论基础。