The use of seed texture features for discriminating different cultivars of stored apples

The aim of this study was to identify the textural features of apple seeds with the highest discriminatory power for distinguishing the seeds of different apple cultivars with the use of discriminative classifiers. The seeds of apple cvs. Gala, Jonagold and Idared were scanned with the use of a flatbed scanner, and the acquired images were processed to calculate textural features from color channels: L, a, b, R, G, B, Y, U, V, H, S, I, X, Y and Z. The selected textures were used to develop discriminative models and distinguish the seeds of the examined apple cultivars. The analyses were performed for color spaces and color channels. The seeds of apple cvs. Gala and Idared were discriminated with 100% accuracy in models based on the textures from Lab and YUV color spaces and color channel L for the Naive Bayes, Multilayer Perceptron and Multi Class classifiers. The discriminatory accuracies of the seeds of all analyzed apple cultivars (Gala, Idared and Jonagold) ranged from 72% to 85%. The discriminatory accuracy of the textures selected from Lab color space for the Naive Bayes classifier reached 85%. The seeds of apple cvs. Gala and Jonagold were discriminated with 78–90% accuracy, and the discriminatory accuracy of the textures from Lab color space and color channel b for the Naive Bayes classifier reached 90%. The seeds of apple cvs. Idared and Jonagold were distinguished with 80–94% accuracy. The models based on textures from Lab color space and color channel b for the Naive Bayes classifier were characterized by 94% discriminatory accuracy. The study demonstrated that textural features are useful for discriminating the seeds of different apple cultivars.     

Dietary fibre content of thirteen apple cultivars

Fibre composition of the following 13 apple cultivars was studied: ‘Cortland’, ‘Empire’, ‘Fuji’, ‘Golden Delicious’, ‘Gala’, ‘Granny Smith’, ‘Jonagold’, ‘Mutsu’, ‘McIntosh’, ‘Delicious’, ‘Rome’, ‘Stayman’ and ‘York’. Fruit samples from each of these cultivars were analysed for non-starch cell wall materials (NSCWM) and non-starch polysaccharides (NSP). NSCWM was further fractionated into soluble and insoluble fibre fractions. Both NSCWM and NSP content were found to be significantly influenced by cultivar. NSCWM content ranged from 19·1 g kg⁻¹ apple flesh in ‘Fuji’ to 36·2 g kg⁻¹ in ‘York’. Mean(±SD) NSCWM content of all the cultivars was 23·1±4·5 g kg⁻¹. NSP content of apple flesh ranged from 13·8 g kg⁻¹ in ‘McIntosh’ to 28·7 g kg⁻¹ in ‘York’ with the overall mean for all cultivars being 17·9±4·2 g kg⁻¹. Relative amount of monosaccharides found in the hydrolysates of apple fibre also varied among cultivars. The greatest difference was observed in galactose content. ©1997 SCI     

Comparative polyphenolic antioxidant profile and quality of traditional apple cultivars as affected by cold storage

‘Kathista’ and ‘Lortiko’ are regarded as traditional and highly appreciated apple cultivars in Cyprus, yet their postharvest behaviour and phytochemical content are largely unknown. Such fruits were examined for their qualitative traits, phenolic composition and antioxidant capacity after harvest or short, intermediate or extended cold storage and additional ripening at room temperature (RT), using ‘Gala’ as reference cultivar. Total phenolic content was dependent on cultivar and length of cold storage, while hydroxycinnamic acids were always at higher levels compared to total flavonols for all the examined cultivars. No clear trends regarding the influence of cold storage or RT maintenance on fruit antioxidant properties were evident. Overall, quality attributes and polyphenolic content of the traditional apple cultivars were comparable with ‘Gala’ at harvest; thus, they can be considered a good source of nutraceuticals as summer apple cultivars. However, extended cold storage deteriorates fruit behaviour and antioxidant capacity, particularly in ‘Lortiko’ fruit.     

Effects of irradiation on respiration and ethylene production of apple slices

Respiration and ethylene production rates of irradiated apple slices from four apple cultivars were measured for 72 h. Doses less than 1.2 kGy had no effect on rates of CO₂ production and O₂ consumption, and irradiation at doses between 1.2 and 2.4 kGy had minimal effect for all cultivars. Respiratory response of ‘Idared’, ‘Law Rome’ and ‘Empire’ slices to irradiation was curvilinear, with maximum respiration occurring in the 3–6 kGy dose range. Response of ‘Delicious’ slices was linear over the irradiation dose range (0–11 kGy) studied. Respiratory quotient increased with irradiation dose. The degree of maturity of the slices affected respiratory responses. Irradiation reduced ethylene production of all slices. These results suggest that irradiation doses of up to 2.4 kGy can be used with minimum effect on the respiratory physiology of tissues. © 2000 Society of Chemical Industry     

Antioxidant enzyme activities in apple varieties and resistance to superficial scald development

The activities and isozyme profiles of superoxide dismutase (SOD), guaiacol peroxidase (POX) and ascorbate peroxidase (APX) were monitored in skin tissues of scald-resistant and scald-susceptible apple cultivars (Malus domestica Borkh.). SOD activity was high in Gala, with moderately high levels in Idared, McIntosh and Delicious, and low levels in Cortland and Empire. Guaiacol peroxidase activities were high in Empire, McIntosh and Delicious, with moderate to low levels in Cortland, Gala and Idared. Ascorbate peroxidase activity was nearly similar in all the cultivars. Native PAGE and activity staining showed great differences in the guaiacol peroxidase isozyme profiles. Ascorbate peroxidase isozyme profiles showed a fast moving isozyme present in all cultivars. Tissue printing for peroxidase in varieties such as Empire and Crispin showed intense activity, especially in the epidermal region. α-Farnesene levels were variable in all the cultivars. The results suggest that other biochemical characteristics in addition to the antioxidant enzyme activities and α-farnesene levels may be involved in determining the susceptibility/resistance to superficial scald development.     

Allergenicity of different apple cultivars assessed by means of skin prick test and sensitisation to recombinant allergens Mal d 1 and Mal d 3 in a group of Italian apple‐allergic patients

To evaluate differences in skin prick test response to apple cultivars in patients with apple allergy, 19 patients (10 adults and 9 children) underwent prick‐to‐prick skin prick test with eleven commercial and noncommercial apple cultivars, and evaluation of specific IgE to apple and recombinant apple allergens Mal d 1 and Mal d 3. The results show that different reactions might be evoked in a single patient by different apple cultivars and also separately for the peel and the pulp of a single cultivar. The cultivars were ranked according to their allergenicity level, being Jonathan, Jonagold, Golden Delicious and Fiesta the most allergenic when considering the pulp and Gala, Fiesta and Golden Delicious for the peel. Further investigations are needed to clarify if a single patient can be allergic only to well‐defined apple cultivars and which allergometric tests are necessary to ascertain this.     

EFFECTS OF THE RATE OF HEATING ON APPLE AND PEAR FRUIT QUALITY

There is evidence that the rate of heating to meet quarantine security impacts fruit quality as well as insect mortality. Linear heating rates, of 4, 6, 8, 10, and 12C/h to treatment temperatures of 44 and 46C were used to treat 8 cultivars of apples (‘Delicious’, ‘Golden Delicious’, ‘Granny Smith’, ‘Fuji’, ‘Gala’, ‘Jonagold’, ‘Braeburn’, and ‘Cameo’) and two cultivars of winter pear (‘d'Anjou’ and ‘Bosc’). Fruit were stored, ripened, and tested for various quality parameters. Scald was controlled, firmness was higher in heat treated fruit, ripening was delayed but uniform in pears, decay organisms were suppressed, red fruit became redder and green fruit remained green, the Brix‐acid ratio (SS/TA) was either unchanged (‘Granny Smith’) or increased. Physiological disorders such as bitter pit were exacerbated by the heat treatment, requiring culling after treatment to avoid storage of fruit so affected.     

Effect of apple cultivar and enzyme treatment on phenolic compounds content during clear apple juice production

The aim of the investigation was evaluation of phenolic compounds content, measured by HPLC method at selected stages of clear apple juice production with pectolytic mash enzymation from ‘Shampion’ and ‘Idared’ apples. Sum of phenolic compounds in ‘Shampion’ mash was significantly higher than in ‘Idared’ mash, 520 and 352 mg kg^?1, respectively. Enzymation of ‘Idared’ mash resulted in a higher phenolic compounds decrease compared to ‘Shampion’, 23% and 14% respectively. Sum of phenolics in juices from ‘Shampion’ for Panzym at 50 °C (366 mg kg^?1) was significantly higher than in juices from ‘Shampion’ for Rohapect at 20 °C and ‘Idared’ for Panzym at 50 °C (256 and 234 mg kg^?1, respectively). The lowest phenolics (95 mg kg^?1) was in juices from ‘Idared’ for Rohapect at 20 °C. There was a positive correlation (R² = 0.933) between phenolics content and antioxidant activity of juices (ABTS^?+). In general, enzymation at 50 °C with Panzym lead to a higher content of the phenolic compounds in juices compared to Rohapect at 20 °C.     

1-Methylcyclopropene postharvest treatment and their effect on apple quality during long-term storage time

The aim of this study was to evaluate the effect of the postharvest treatment by 1-methylcyclopropene (1-MCP) and storage time on the apple physicochemically quality. The effects of apple storage during 6 months on basic parameters such as dry weight, total soluble solids and titratable acidity, composition of phenolics, antioxidant activity and sensory evaluation were studied to evaluate the potential applicability of long-time stored apples for consumption and processing. Long-time storage of apples resulted in a higher dry matter but decreases total soluble solids and titratable acidity in all examined cultivars (cv.) of apples. The total phenolics determined by HPLC in fresh apples ranged from 1,243 mg in ‘Idared’ cv. to 1,435 mg/kg in ‘Shampion’ cv. During storage, the decrease of polyphenolic content has been observed, in ‘Shampion’ cv., it was higher than in ‘Idared’ cv. Similar effects were observed for antioxidant activity. Comparing quality of fruits just after harvest, it was found that cultivar affects most of the investigated sensory attributes with the exception of ripe apple smell, crispness, crunchiness and the overall texture score. In general, ‘Shampion’ cv. apples got higher ranks for sweetness, taste and the overall quality, whereas ‘Idared’ cv. were perceived as sourer, which is in arrangement with instrumental measurements. The results of presented study demonstrate that apples after storage, especially ‘Shampion’ cv., can be a valuable sensory attributes for food product and consumption. This study indicates that the use of 1-MCP treatment in long-term storage of apples is promising for maintaining the eating quality of fruits, however, in some extent may affect their antioxidant compounds content.     

DEVELOPMENT OF A PHOTOGRAPHIC SCALE FOR THE VISUAL EVALUATION OF APPLE STRIPE DENSITY1

This research developed a photographic scale for the evaluation of stripe density for 5 apple cultivars (Carousel, 8M-15-10, Fuji, Gala, and Jonagold) using a series of two experiments. In Experiment 1, subjects were able to significantly discriminate and reproducibly score the stripe density of apples using unstructured graphic line scales. Photographs of selected apples were then labelled with the corresponding mean scores and used as visual references for Experiment 2. In Experiment 2, subjects reproducibly evaluated the stripe density of apples using structured line scales (anchored with 3 or 5 photographic references), with similar mean scores from the 3- or 5-point scales. Subject differed very little in their variances reflecting the potential usefulness of these line scales for commercial evaluation of apple stripe density in whole apples.     

Effects of 1‐MCP applied postharvest on epicuticular wax of apples (Malus domestica Borkh.) during storage

BACKGROUND: Certain apple cultivars develop a greasy feel when overripe. Treating fruits with the ripening inhibitor 1‐methylcyclopropene (1‐MCP, SmartFresh^™) reduces fruit greasiness. This study examines the nature of this phenomenon. ‘Royal Gala’ apples were treated with 1‐MCP at 1.0 µl L⁻¹ following harvest. Periodically, during storage at − 1 °C for up to 6 months, fruits were evaluated for internal ethylene concentration, fruit epicuticular wax morphology (using scanning electron microscopy) and non‐polar organic solvent‐extractable (NPOSE) wax constituents of the cuticle (using gas chromatography/mass spectrometry). RESULTS: In 2004, 1‐MCP strongly inhibited internal ethylene production; however, total weight of NPOSE wax during storage was unaffected by treatment. In 2005, several wax constituents present in both ‘Autumn Gold’ and ‘Royal Gala’ showed differences during storage. In 2006, cuticular wax constituents comprising 80% of the total from ‘Royal Gala’ showed no treatment differences. Although several minor constituents did exhibit differences within treatment and sampling date, these did not appear sufficient to cause the subtle differences in surface wax morphology. CONCLUSION: 1‐MCP strongly inhibited ethylene production and delayed development of certain wax constituents thought responsible for fruit greasiness during cold storage. Subtle differences in surface wax morphology appeared unrelated to wax production. Published in 2008 by John Wiley & Sons, Ltd.     

Fruit dry matter concentration: a new quality metric for apples

BACKGROUND: In the fresh apple market fruit must be crisp and juicy to attract buyers to purchase again. However, recent studies have shown that consumer acceptability could be further enhanced by improving taste. This study evaluates the use of fruit dry matter concentration (DMC) as a new fruit quality metric for apple. RESULTS: Fruit samples collected at harvest, in the two main fruit growing regions of New Zealand, showed a variation in mean fruit DMC from 130 to 156 g kg^?1 with ‘Royal Gala’ and with ‘Scifresh’ from 152 to 176 g kg^?1. Individual fruit DMC showed a larger range, from 108 to 189 g kg^?1 with ‘Royal Gala’ and from 125 to 201 g kg^?1 with ‘Scifresh’. Fruit DMC proved a more reliable predictor of total soluble solids after 12 weeks of air storage at 0.5 °C than TSS at harvest for both ‘Royal Gala’ and ‘Scifresh’. Fruit DMC was also positively related to flesh firmness, although this relationship was not as strong as that seen with soluble solids and was more dependent on cultivar. Consumer studies showed that consumer preference was positively related to fruit DMC of ‘Royal Gala’ apples. CONCLUSION: Fruit DMC can therefore be measured before or at harvest, and be used to predict the sensory potential for the fruit after storage. Copyright © 2010 Society of Chemical Industry     

Differentiation of volatile aroma components in organically and conventionally produced apples by stir bar sorptive extraction combined with gas chromatography and EI/CI TOF mass spectrometry

Volatile aroma components and contents of organically and conventionally produced apples of the cultivars Elstar, Jonagold, Jonagored and Braeburn were studied. In three cultivars investigated, the aroma contents of organically produced apples were significantly lower (Elstar 16%, Jonagold 29%, Jonagored 68%). For Braeburn, no statistically significant difference was observed. In particular, the main aroma components were present at much lower concentrations in organically produced apples. In all apple cultivars, these were hexanal, trans-2-hexenal, 2-methylbutylacetate and hexylacetate. twenty-three aroma components were identified in total, in different relative ratios in the different apple cultivars: saturated esters, saturated and unsaturated aldehydes and alcohols. Some components identified in the conventionally produced cultivars were not present in the organically produced cultivars at all. The aroma components were extracted from juice freshly prepared from the apples by stir bar sorptive extraction (SBSE) technique and characterised by FID gas chromatography and EI/CI TOF mass spectrometry.     

Effects of various clarification treatments on phenolic compounds and color of apple juice

The purpose of this study was to investigate the changes that occur during conventional clarification using gelatin, bentonite, silica sol, and water-soluble chitosan on the phenolic compounds, antioxidant activity, and color of apple juice. The apple material used in this study was of two varieties: Sampion and Idared. The changes in the polyphenols composition (procyanidins, hydroxycinnamic derivatives, and dihydrochalcones) were monitored through the clarification process. Sampion apple control juices contained more total polyphenols than do Idared apple juices. In Sampion variety apple juice, the dominant polyphenols are the flavan-3-ols (86% of total polyphenols), followed by hydroxycinnamic acids (9.7%), dihydrochalcones (3.0%), and flavonols (1.3%). In Idared apple juice the hydroxycinnamic acids (especially chlorogenic acid) are dominant (about 48% of total polyphenols), followed by flavan-3-ols (40%). However, the concentration of polymeric procyanidins in Sampion apple juices was 62.8 and 46.3% less when the Profloc (chitosan) and gelatin treatments were used, respectively. Aktivbentonit and Puranit (bentonite) supplementary added in juices clarification have some protective effect on polymeric procyanidins only with Profloc treatment. That kind of effect was not observed in Idared apple juices with almost eight times smaller polymeric procyanidins concentration than in Sampion apple juices. The antioxidant activity, measured by the DPPH (1,1-diphenyl-2-picrylhydrazyl radical) method, ranged from 0.20 mg TEAC/mL in Idared apple juice to 0.30 mg TEAC/mL in Sampion apple juice, measured by the ABTS method, from 0.17 to 0.48 mg TEAC/mL, respectively. Clarification of apple juices with chosen clarifying agents has statistically no significant (p>0.05) influence on antioxidant capacity. This study suggests that chitosan can be used as a conventional clarifying aid of apple juices and that treatment has no impact on their biochemical parameters.     

纳米SiOx保鲜果蜡对苹果贮藏性能的影响

以"乔纳金"和"红富士"为试材,研究了纳米SiOx保鲜果 蜡对两个品种苹果果实的呼吸强度、失重率、硬度和可溶 性固形物含量变化的影响。实验结果表明,纳米SiOx保 鲜果蜡有效抑制了果实的呼吸强度,显著降低了果实的 失重率,延缓了果实硬度和可溶性固形物含量的下降(p< 0.05),其对苹果货架期的延长已经与进口果蜡相近,某些 性能甚至优于进口果蜡。     

中早熟苹果品种的贮藏品质和酚类物质差异分析

中早熟苹果品种可以丰富水果市场,是苹果产业重要的组成部分,研究其贮藏特性及品质差异意义重大。本实验以‘鲁丽’‘鲁艳’两个苹果新品种为研究对象,以其亲本‘嘎啦’为参照,探究3种苹果的贮藏品质和酚类物质差异。结果表明：相比于‘嘎啦’苹果,‘鲁丽’苹果可溶性固形物质量分数最高,果皮a*值最大,外观品质最佳、适于鲜食,而‘鲁艳’苹果总酸度高、固酸比低,贮藏期间乙烯释放量高,不耐贮藏。与‘嘎啦’和‘鲁艳’苹果相比,‘鲁丽’苹果有着最高的总酚、总黄酮含量和1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除率,抗氧化能力最强。3种苹果主要的酚类物质也因品种、成熟度和果实部位存在差异,‘嘎啦’和‘鲁丽’苹果果肉均以绿原酸含量最高,而‘鲁艳’苹果表儿茶素含量最高,果皮酚类物质含量高于果肉。相关性和主成分分析表明果实硬度与a*值有高度显著负相关性（P<0.001）,可溶性固形物质量分数与总酚、总黄酮、绿原酸含量和DPPH自由基清除率存在高度显著正相关（P<0.001）,主成分1主要由总酚、总黄酮、绿原酸、表儿茶素含量等指标决定,成熟...     

黄土高原旱塬区不同品种苹果果实糖及有机酸含量比较分析

为明确黄土高原旱塬区不同品种苹果果实中糖与有机酸含量的特征,对主栽的30个品种果实中糖、酸类物质含量进行分析。采用高效液相色谱法（High-phase liquid chromatography,HPLC）对30个品种成熟期果实中可溶性糖与有机酸含量进行了测定,并对数据进行单因素方差分析与相关性分析。结果表明:不同品种苹果果实糖组分中果糖含量最高,均值为52.964 mg/g,占总糖含量的48.82%,且二者呈极显著性相关（r=0.787）,果糖含量最高的品种为‘嘎啦’（69.736 mg/g）,大部分品种果实中蔗糖含量高于葡萄糖含量,只有3个品种表现出葡萄糖含量高于蔗糖含量,分别为‘金冠’、‘八月富士’和‘无锈金矮生’;不同品种苹果果实酸组分中苹果酸含量最高,均值为3.857 mg/g,占总酸含量的57.44%,且二者呈极显著性相关（r=0.845）,奎宁酸含量次之,其他种类有机酸含量较低,苹果酸含量最高的品种为‘寒富’（8.109 mg/g）;甜度值/总酸含量大于30的品种有3个,分别为‘世界1号’、‘金冠’和‘嘎啦’,介于20～30之间的品种有13个,小于20的品种有14个。苹果果实中甜度值和总酸含量、以及甜度值与总酸含量的比值共同影响果实风味。     

Changes of contents and antioxidant activities of polyphenols during fruit development of four apple cultivars

Polyphenols are functional components in apples and can be separated into four groups by Sephadex LH-20 as epicatechin, procyanidolic oligomers, chlorogenic acid and procyanidolic polymers. Antioxidant activities of each group were determined by FRAP and DPPH radical scavenging assay. It was found that procyanidolic oligomers and procyanidolic polymers influenced the total polyphenols content (measured by Folin–Ciocalteu method) much more in Jonagold, Golden Delicious, Fuji and Guoguang four apple cultivars. The Fe-reducing activity of procyanidolic oligomers in the four apple cultivars increased significantly during the development while the other three compounds changed irregularly. And the Fe-reducing activities of epicatechin and procyanidin contributed much more to the total Fe-reducing activities during the fruit development in the four apple cultivars. The DPPH scavenging activities of four compounds in Jonagold and Golden Delicious decreased during fruit development and that of Fuji and Guoguang changed irregularly. Chlorogenic acid was the main contributor in Jonagold, Golden Delicious and Fuji to the total scavenging activity. In Guoguang, it was procyanidolic oligomers that contributed much to the total scavenging activity.     

Variation among physical,chemical and technological properties in three Sicilian cultivars of Chickpea (Cicer arietinum L.)

Three Sicilian chickpea cultivars (‘Calia’, ‘Etna’ and ‘Principe’) were evaluated for physical, chemical and technological properties. Whereas no substantial differences were ascertained on seeds chemical composition, the cultivars greatly differed in terms of seed size, specific surface area (SSA) and seed coat incidence. These last two properties affected the technological properties of the seeds. In particular, a high SSA (‘Calia’) contributed to a faster softening, whilst a great coat thickness (‘Etna’) delayed both hydration and softening rate. The time required to obtain an acceptable firmness (cooking time) was greatly reduced by presoaking the seeds in salt solution (0.5% NaCl or NHCO₃). ‘Calia’ required the lowest cooking time when soaked in distilled water or in 0.5% NaCl. Presoaking seed in NaHCO₃ allowed halving the cooking time in all cultivars.