Time of methyl jasmonate application influences the development of ‘Cripps Pink’ apple fruit colour

BACKGROUND: The effects of time and numbers of pre‐harvest sprays of methyl jasmonate (MJ) on the development of red blush, export‐grade fruit, accumulation of flavonoids in fruit skin and quality of ‘Cripps Pink’ apple were investigated in 2005 and 2006. In the first experiment during 2005, whole trees were sprayed once with 10 mmol L^?1 MJ at weekly intervals from 155 to 183 days after full bloom (DAFB). In second experiment during 2006, different numbers of sprays (0, 1, 2, 3, 4, 5 or 6) of 5 mmol L^?1 MJ were applied from 151 to 179 DAFB. RESULTS: A single spray of MJ (10 mmol L^?1) at 169 DAFB resulted in the highest increase in the red blush, export‐grade fruit, accumulation of anthocyanins, cyanidin 3‐galactosides, chlorogenic acid, phloridzin, flavanols and flavonols in fruit skin as compared to all other treatments without affecting fruit quality. A single spray of 5 mmol L^?1 MJ at 186 DAFB was more effective in improving red blush, export‐grade fruit and accumulation of anthocyanins in fruit skin as compared to its multiple applications. The exposed sides of fruit developed better colour than the shaded sides, regardless of time and numbers of MJ sprays. Time of a single spray of MJ is more effective than its multiple applications. CONCLUSIONS: A single pre‐harvest spray of MJ (10 mmol L^?1) at 169 DAFB or MJ (5 mmol L^?1) at 186 DAFB was effective in improving the red blush and export grade fruit through accumulation of flavonoids in fruit skin without adversely affecting quality at harvest. © 2012 Society of Chemical Industry     

Chlorophylls,carotenoids and anthocyanin concentrations in the skin of ‘Gala’ apples during maturation and the influence of foliar applications of nitrogen and magnesium

‘Gala’ apple fruit were sampled over two growing seasons, to determine the effects of maturation, and of foliar applications of nitrogen and magnesium on pigment concentrations and colour development in maturing fruit. Treatments of urea and/or magnesium sulphate sprays were applied to the trees in a commercial orchard. The chlorophyll, carotenoid and anthocyanin concentrations in the fruit skin were determined for both the blush and back sides over 15 harvests in 1991–1992. In 1990–1991, the skin chlorophyll concentrations were determined only for the back side of the fruit. The fruit nitrogen, magnesium and sulphur concentrations were determined near maturity. The concentrations of chlorophyll and carotenoids in apple skin decreased from the first harvest in 1991–1992 as the fresh weight increased from 12 g, 40 days from flowering to 140 g, 138 days from flowering. Chlorophyll continued to decrease whereas carotenoid concentrations increased after 138 days and until at least 153 days. The average skin chlorophyll and carotenoid concentrations were higher on the blush side of the fruit than on the back. The total chlorophyll per fruit increased from the first harvest to a peak about 70 days after flowering in 1990–1991 and then decreased over the remainder of the period studied. The time of this peak was about 40 days later in the 1991–1992 season compared with the 1990–1991 season. The total carotenoid increased up to about 50 days after flowering in 1991–1992, fluctuated and then decreased up to 138 days when the amount increased again. The ratio of carotenoids to chlorophylls was highest for the first three harvests, fluctuated somewhat up to c 138 days after flowering after which the ratio increased rapidly. The anthocyanin concentrations were low and fluctuated up to 130 days from flowering and then increased markedly only on the blush side at 130 days, about 14 days before the carotenoids started to increase. The treatment of the tree canopy with urea increased the chlorophyll and carotenoid concentrations in the fruit skin, 14–20 days after the first application until after maturity, more so on the blush side than on the back side. These increased concentrations were maintained up to the harvest after which carotenoid concentrations increased. The urea treatment lessened the increase of anthocyanin concentrations in the blush side skin of the fruit, at maturity. At maturity, the nitrogen concentration of fruit from urea treated trees was higher than those from untreated trees. The magnesium sulphate treatment of the canopy increased the chlorophyll and carotenoid concentration on the back of the fruit within 20–30 days from commencing spraying. The ‘ground colour’ scores for the back sides of the fruit (used for fruit picking and grading) were greener for the urea treated fruit and reached an acceptable score about two weeks later than the untreated fruit. ©1998 SCI     

Effect of nano‐ZnO‐coated active packaging on quality of fresh‐cut ‘Fuji’ apple

A novel nanopackaging was synthesised by coating polyvinyl chloride (PVC) film with nano‐ZnO powder, and its effects on the preservation quality of fresh‐cut ‘Fuji’ apple were investigated at 4 °C for 12 days. Compared with the control (PVC film), nanopackaging significantly reduced the fruit decay rate (P < 0.05), as well as decreased the accumulation of malondialdehyde (MDA) from 74.9 nmol g^?1 in the control to 53.9 nmol g^?1 in the nanopackaging. Cutting caused an increase in ethylene level, suggesting wound‐induced ethylene production, which was suppressed in nanopackaging. Both the polyphenoloxidase and pyrogallol peroxidase activities were decreased in nanopackaging fruit. The initial appearance of apple slices was retained, and the browning index was prevented in nanopackaging samples, which was only 23.9, much lower than the control of 31.7 on day 12. These results indicated that nano‐ZnO active packaging could be a viable alternative to common technologies for improving the shelf‐life properties of ‘Fuji’ apples as a fresh‐cut product.     

Fruit quality of ‘Fuji’ apple (Malus domestica Borkh.) strains

‘Fuji’ is an attractive apple for consumers owing to its desirable internal (low acidity, high sugar and phenols) and external (firmness, colouration) fruit quality. However, its red colouration is often weak and starts late in the season. Therefore, in 2003 and 2004, three ‘Fuji’ strains, ‘Kiku 7’, Kiku 8' and ‘Naga‐fu 6’, and standard ‘Fuji’ were compared in terms of fruit quality by high‐performance liquid chromatography analysis in order to determine their contents of fruit sugar, organic acids and phenols. The % and intensity of red top colour were also analysed. Of the three strains, ‘Kiku 8’ proved to have the best red colouration and accumulated the largest amount of reducing sugars with the lowest quantity of phenols in both years examined. The quality parameters of strains ‘Kiku 7’ and ‘Naga‐fu 6’ fell between those of standard ‘Fuji’ and ‘Kiku 8’. ‘Kiku 8’ may be the most suitable for areas with high variations in daily and nightly temperatures to obtain the best colour development. Under conditions with warm days and cool nights the other strains and standard ‘Fuji’ can develop a proper coloured fruit of high quality. Copyright © 2007 Society of Chemical Industry     

陕西洛川富士鲜苹果品质综合评价及分级体系的构建

建立鲜苹果品质综合评价标准及分级标准,构建鲜苹果品质的综合评价及分级体系,为鲜苹果品质在线无损检测提供技术支撑。以陕西洛川富士苹果为材料,利用SPSS 19.0软件通过因子分析对鲜苹果13 项品质指标进行筛选,利用概率分布和层次分析分别进行品质评价指标的分级及指标权重的确定,再通过K-均值聚类分析和判别分析建立苹果品质判别函数模型。本实验筛选出陕西洛川富士鲜苹果的7 项主要品质指标：单果质量、果形指数、色泽a*值、可溶性固形物含量、硬度、VC含量、糖酸比,建立了主要品质指标的分级标准和评分标准,得到对鲜苹果品质综合评价的5 个判别函数,建模样本和检验样本的判别正确率分别达95.65%和91.67%。     

Non‐destructive prediction of ‘Hass’ avocado dry matter via FT‐NIR spectroscopy

BACKGROUND: The inability to consistently guarantee internal quality of horticulture produce is of major importance to the primary producer, marketers and ultimately the consumer. Currently, commercial avocado maturity estimation is based on the destructive assessment of percentage dry matter (%DM), and sometimes percentage oil, both of which are highly correlated with maturity. In this study the utility of Fourier transform (FT) near‐infrared spectroscopy (NIRS) was investigated for the first time as a non‐invasive technique for estimating %DM of whole intact ‘Hass’ avocado fruit. Partial least squares regression models were developed from the diffuse reflectance spectra to predict %DM, taking into account effects of intra‐seasonal variation and orchard conditions. RESULTS: It was found that combining three harvests (early, mid and late) from a single farm in the major production district of central Queensland yielded a predictive model for %DM with a coefficient of determination for the validation set of 0.76 and a root mean square error of prediction of 1.53% for DM in the range 19.4–34.2%. CONCLUSION: The results of the study indicate the potential of FT‐NIRS in diffuse reflectance mode to non‐invasively predict %DM of whole ‘Hass’ avocado fruit. When the FT‐NIRS system was assessed on whole avocados, the results compared favourably against data from other NIRS systems identified in the literature that have been used in research applications on avocados. Copyright © 2010 Society of Chemical Industry     

Polyphenoloxidase activity and total phenolic content as related to browning of minimally processed ‘Jonagored’ apple

Phenolic content, polyphenoloxidase (PPO) activity and browning have been reported by different authors to vary in different ways, depending on cultivar, picking maturity, storage conditions, etc. Numerous authors have attempted to correlate browning results with the phenolic content and/or enzymatic activity of apples, but data published in the literature are divergent as to which of the two factors, ie the enzyme or the substrate, plays the decisive role in the overall phenomenon of enzymatic browning. The aim of this work was to follow the PPO activity and phenolic content of minimally processed apple (cv ‘Jonagored’) during cold storage and to establish a potential relationship with enzymatic browning. Increasing storage time of minimally processed apple seemed to result in an increase in PPO activity. No changes (P > 0.05) in total phenolic content were observed during storage. Colour degradation of apple cubes, as indicated by changes in colour parameters, was found to be highly correlated with PPO activity. Browning of ‘Jonagored’ apple cubes during storage was found to be moderately correlated with PPO activity. No correlation was found between the browning index and the total phenolic content. © 2001 Society of Chemical Industry     

Variety‐based discrimination of apple juices by an electronic nose and gas chromatography–mass spectrometry

The variety of raw material plays a crucial role in the quality and authenticity of fruit juices and juice products. To characterise and classify apple juices according to variety on the basis of their volatile compounds, electronic nose (EN) and gas chromatography–mass spectrometry (GC‐MS) were applied to detect the apple juices prepared by eight different varieties. The EN was used to analyse the mixture of volatile compounds as a whole and enabled rapid classification of juice samples when coupled with linear discriminant analysis (LDA). LDA showed a perfect discrimination of apple juices based on varieties. GC‐MS was utilised to illustrate the differences of volatile compounds among juice samples. Identification of volatile compositions and their contents provides useful access to differentiate juices from different varieties.     

基于隐马尔科夫模型的苹果分级方法研究

提出了一种基于隐马尔科夫模型的苹果分级方法。以3种不同颜色和形状的苹果为研究对象,提取苹果的六角锥体模型(HSV)作为苹果的颜色特征,提取苹果Hu不变矩作为苹果的形状特征,将这些特征量采用Lloyd算法编码,并将它们作为隐马尔科夫模型(HMM)的输入。依据HMM模式识别方法,对不同颜色和形状的苹果进行了分类识别,进而完成苹果分级。试验表明,该方法完成的分级识别率为100%。     

Quality evaluation of chickpeas using an artificial neural network integrated computer vision system

Chickpea is one of the most consumed legumes in the world. The classification of chickpea based on the size and morphological properties is important for the market. The objective of this study is to design and implement a computer vision system (CVS) integrated with artificial neural networks (ANN) for quality evaluation of chickpeas based on their size, colour, and surface morphology. The system is composed of a flat bed scanner for acquiring digital image and software that has been developed in Matlab for image analysis. Physical properties (length, width and volume) of the samples of chickpeas as well as their colour properties and surface characteristics have been determined by using the system, and results have been validated. High correlations have been found between the results from ANN‐integrated CVS and those obtained by callipers or professionally trained inspectors based on the experiments. Overall, percentages of correct classification have been determined as 95.4%, 87.6%, and 96.0% for colour, surface morphology, and shape evaluations, respectively.     

Delayed harvest and cold storage period influence ethylene production,fruit firmness and quality of ‘Cripps Pink’ apple

The effects of harvest date and cold storage period on ethylene production, fruit firmness and quality of ‘Cripps Pink’ apple were investigated. Fruit were harvested from Perth Hills and Donnybrook (Western Australia) at commercial maturity (CM), 2, 4 and 6 weeks after CM prior to 0, 45, 90 and 135 days cold storage in 2003 and 2004. Delayed harvest significantly increased ethylene production, CIE values a* and C* at both locations in 2 years. Delayed harvest and extended cold storage period increased the internal ethylene production and reduced fruit firmness, soluble solids concentration: titratable acidity (SSC:TA) ratio and reduced CIE values L*, b*, h° during both years and locations. Fruit harvested 2 weeks after CM can be cold‐stored for 90 days with acceptable fruit quality. If the fruit is intended to be sold fresh immediately in local markets, the harvest can be delayed up to 6 weeks after CM to harness substantially improved fruit colour with acceptable fruit quality.     

DEVELOPMENT OF A VOCABULARY FOR PROFILING APPLE JUICES

A protocol for selecting an apple juice lexicon and for training a company panel was developed, using a series of 21 ‘taste’ sessions. Individual assessment, round‐table discussion and consensus were used to identify reference standards for six aroma and 11 flavor attributes and 13 ‘off ‘notes. Duo‐trio tests were used to test the ability of the panelists to recognize the references and confirm their appropriateness in describing the attribute. When panelists' mean scores for the references were placed as anchors on the line scales, panel performance was improved. The development process not only served to train the panel, but was a ‘team’ building experience which benefited the company at large.     

Development and characterisation of a sugar‐free milk‐based dessert formulation with fig (Ficus carica L.) and carboxymethylcellulose

The objective of this study was to develop an optimum formula for ‘Shir Anjir’, an Iranian dessert containing milk, dried fig (13, 16.5, 20%) and carboxymethylcellulose (CMC) (0, 0.35, 0.7%) with no added sugar. Apparent viscosity, flow behaviour indices, pH, acidity (% lactic acid), total solid and colour parameters were compared. Sensory tests were performed to evaluate degree of liking of colour, appearance, taste, texture, mouthfeel and general acceptance. Figs and CMC influenced the dessert's characteristics. The most popular formula contained milk, 16.5% figs and 0.7% CMC and had an apparent viscosity of 3.78 Pa·s at 5 °C, exhibiting a shear‐thinning behaviour.     

Instrumental measurement of orange juice colour: a review

Colour of orange juice is provided by carotenoids, which belong to one of the main classes of natural pigments, although the colour of particular orange varieties, blood oranges, is mainly due to anthocyanins. Colour of food influences consumers' preferences. For orange juices, some studies have revealed that the colour of citrus beverages in general is related to the consumer's perception of the quality of these products. The USA attaches great importance to the objective evaluation of orange juice colour, to the point that this attribute is evaluated for the commercial classification of the product on the basis of its quality. Apart from the importance of orange juice colour in relation to the quality of the product, it is important to accurately measure this parameter since it has been demonstrated that colour measurements can be used to estimate the carotenoid content rapidly for quality control purposes. Owing to this factors, several techniques and instruments have been developed over the years. This review assesses these methods and the results gained from them. Copyright © 2005 Society of Chemical Industry     

A rapid non‐destructive method for fish quality control by determination of smell intensity

The ‘Cosmos’ instrument (Japan) was applied to the evaluation of fish quality in six species of different origins, by determination of smell intensity. Pond‐raised fish (trout, carp, silver perch, tilapia, barramundi) were stored in ice for 4–5 weeks and frozen/thawed mackerel was kept at room temperature for 74 h. The fish quality was examined by organoleptic assessment, by determination of smell intensity and by tests of the chemical (total volatile basic nitrogen, hypoxanthine and histamine) and dielectric (Torrymeter) properties. Strong correlation was found between the organoleptic and ‘Cosmos’ results, whereas the data from the chemical and Torrymeter analyses were relatively poorly correlated with the sensory evaluation and ‘Cosmos’ data. Thus the application of the ‘Cosmos’ instrument for objective quantitative evaluation of fresh and chilled fish quality by determination of smell intensity seems practicable. The ‘Cosmos’ instrument is hand‐held and portable as well as being rapid and non‐destructive in operation; therefore it could be used for evaluation of fresh and chilled fish in the field and on board fishing vessels. Copyright © 2003 Society of Chemical Industry     

DETERMINATION OF FIRMNESS AND SUGAR CONTENT OF APPLES USING NEAR‐INFRARED DIFFUSE REFLECTANCE1

The objective of this research was to study the potential of near‐infrared (NIR) diffuse reflectance between 800 nm and 1700 nm for determining the firmness and sugar content of apples and to ascertain the effects of apple peel and variety on the NIR prediction of these two quality attributes. The spectral reflectance data were acquired from both peeled and unpeeled ‘Empire', ‘Golden Delicious', and ‘Red Delicious’ apples. Statistical models were developed using principal component analysis/regression. Lower correlations of prediction were obtained (r=0.38 to 0.58) between NIR measurement and Magness‐Taylor firmness for both unpeeled and peeled fruit, with the standard errors of prediction (SEP) between 6.6 N and 10.1 N. Improved predictions were obtained when NIR reflectance was correlated with the slope of the Magness‐Taylor force‐deformation curves. Excellent predictions of the sugar content in peeled apples were obtained (r=0.93 to 0.97; SEP=0.37 to 0.42 °Brix). The SEP, on average, increased by about 0.17 °Brix for the unpeeled apples. Variety did not have a large effect on the model performance on sugar content predictions.     

Discrimination of climacteric and non‐climacteric melon fruit at harvest or at the senescence stage by quality traits

BACKGROUND: This paper characterizes the quality traits at harvest and the changes associated with fruit senescence based on fruit physiological behaviour (climacteric or non‐climacteric) found in a collection of near‐isogenic lines (NILs) of melon (Cucumis melo L.). Data from both stages of postharvest development were analyzed by univariate and multivariate statistical analysis. RESULTS: The principal components and random forest analyses of the fruit quality traits allowed the best classification of the NILs by time (harvest, senescence), or by climacteric behaviour at harvest, but not at the senescent stage. The overall quality profile of the non‐climacteric senescent melons was, in general, very different from that of the climacteric ones, and was in accord with a longer storage life. Most of the taste quality traits (individual sugars or sucrose equivalents, titratable acidity and the citric, oxalacetic, glutamic and succinic acids) and the traits related to skin, flesh and juice colour parameters (chroma, hue angle) helped to distinguish the climacteric NILs from the non‐climacteric ones independently of the time considered. CONCLUSIONS: The time had a stronger effect on quality than the physiological behaviour. The discrimination by climacteric or non‐climacteric behaviour was usually better at harvest than at the senescent stage irrespective of the methodology used. Principal component analysis was the best multivariate method to discriminate by time and physiological behaviour followed by random forest and linear discriminant analysis. Copyright © 2009 Society of Chemical Industry     

Quality grading of Atlantic salmon (Salmo salar) by computer vision

ABSTRACT:  In this study, we present a promising method of computer vision-based quality grading of whole Atlantic salmon ( Salmo salar ). Using computer vision, it was possible to differentiate among different quality grades of Atlantic salmon based on the external geometrical information contained in the fish images. Initially, before the image acquisition, the fish were subjectively graded and labeled into grading classes by a qualified human inspector in the processing plant. Prior to classification, the salmon images were segmented into binary images, and then feature extraction was performed on the geometrical parameters of the fish from the grading classes. The classification algorithm was a threshold-based classifier, which was designed using linear discriminant analysis. The performance of the classifier was tested by using the leave-one-out cross-validation method, and the classification results showed a good agreement between the classification done by human inspectors and by the computer vision. The computer vision-based method classified correctly 90% of the salmon from the data set as compared with the classification by human inspector. Overall, it was shown that computer vision can be used as a powerful tool to grade Atlantic salmon into quality grades in a fast and nondestructive manner by a relatively simple classifier algorithm. The low cost of implementation of today's advanced computer vision solutions makes this method feasible for industrial purposes in fish plants as it can replace manual labor, on which grading tasks still rely.     

Multivariate analysis of maturity stages,including quality and aroma,in ‘Royal Glory’ peaches and ‘Big Top’ nectarines

Ethylene production, quality attributes and aroma compounds were analysed to determine the maturity evolution of ‘Big Top’ nectarines and ‘Royal Glory’ peaches at harvest dates ranging from 89 to 116 days after full bloom (DAFB) for nectarines and from 85 to 112 DAFB for peaches. These cultivars are highly coloured even in the early stages of maturity. However, the two cultivars had different patterns of ethylene production, this being slower in nectarines than in peaches. Principal component analysis (PCA) was used to provide partial visualisation of the complete data set in a reduced dimension plot. Separation of the two cultivars can be shown by means of a two‐dimensional plot of the samples. Although only some aroma compounds are slightly correlated with quality parameters, when aroma volatiles were included in the PCA, the aroma compound set allowed both cultivars to be classified into three stages of maturity: immature, intermediate and fully mature. Compounds such as propanol, hexyl acetate, 2‐methylpropyl acetate, limonene, butanol, (Z)‐3‐hexenyl acetate, buthyl acetate, linalool, ethanol, propyl acetate and ethyl acetate are the most important volatiles for ‘Big Top’ nectarines. It is suggested that the presence of these compounds can be used to indicate when the fruit should be harvested. The presence of γ‐decalactone, δ‐octalactone, γ‐octalactone, ethyl butyrate, hexanal and (E)‐2‐hexenol can be used to indicate the harvesting maturity stage for ‘Royal Glory’ peaches. The optimum maturity date for harvest would be 105–107 DAFB for ‘Big Top’ nectarines and 93–95 DAFB for ‘Royal Glory’ peaches. © 2002 Society of Chemical Industry     

The relationship between the subjective and objective measurement of pork colour

Summary. The colour of ninety-seven pig longissimus dorsi muscles was measured using a spectrophotometer, a simple colour reflectometer, and an untrained panel of ten graders. the results obtained from the colour meters and the graders were compared with Munsell V value of the samples, calculated from the reflection spectra.
Visual colour grading produced a near linear correlation with the Munsell V value. Dark samples tended to be underestimated, whereas pale samples were overestimated by the panel. There was considerable variation between observers'scores, between methods of visual grading, and between visual and instrumental grading. Results obtained from the colour meter were reproducible. the error in comparison with the spectrophotometer was small. the colour meter provides a convenient portable and inexpensive method of measuring the colour lightness of pork muscle.
The experiment showed the practicability of objective measurement of meat colour lightness. the determination of colour quality, however, requires both subjective and objective measurements.