Analysis of the changes in quality in mandarin fruit,produced by deficit irrigation treatments

‘Clemenules’ mandarin citrus trees, grafted on Cleopatra and Carrizo rootstocks, were subjected to three irrigation treatments: the control (100% ETc), and phases II and III treatments (non-irrigation during phases II and III, respectively). The two deficit irrigation (DI) treatments affected in different ways some fruit quality parameters and these effects were also dependent on the rootstock. Although phase II treatment increased total soluble solids (TSS) and titratable acidity (TA), it delayed the maturation process. Phase II-stressed fruits on Carrizo had more fructose and glucose but less sucrose in relation to control fruits, thus increasing the reducing sugars. Phase II-stressed fruits on Cleopatra had more glucose, fructose and sucrose, for osmotic adjustment, also increasing the reducing sugars in these fruits. Phase III-stressed fruits had greater acidity, TSS, total phenolics, lycopene, glucose and sucrose than control fruits, but the same maturation state. In conclusion, DI in phase III improved fruit quality, by increasing the values of important quality parameters related to taste, flavour and nutritional benefits, but DI in phase II produced a drastic delay in the maturation process that made fruits non-commercial.     

Effect of sucrose‐based polymers on quality of Satsuma mandarin fruit (Citrus unshiu Marc. cv. Miyagawa Wase)

In this study, the effects of an edible coating (sucrose‐based polymers, SBP) on postharvest fruit quality of Satsuma mandarin (Citrus unshiu Marc. cv. Miyagawa Wase) were investigated. All the fruit except the control was sprayed with SBP solution at a concentration of 0.1%, 0.3%, 0.5% and 1.0% (v/v), respectively, and then stored at room temperature (25 °C, 85% relative humidity) for 25 days. Results showed that 0.1%, 0.3% and 0.5% SBP treatment could significantly increase the soluble solids concentrations (SSC), vitamin C (Vc), total sugars, total carotenoids, the ratio of SSC to titratable acidity (TA) (SSC/TA), catalase (CAT), peroxidase (POD) and superoxidase dismutase (SOD) activities, while the decay rate, TA and polyphenol oxidase (PPO) activity were greatly reduced. In contrast, 1.0% SBP treatment resulted in fruit browning, despite maintaining fruit quality. Our present study provided the theoretical data for the practical application of the SBP on the citrus fruit quality of during postharvest storage.     

邻苯基苯酚结合果蜡涂膜处理对采后贡柑贮藏品质的影响

为延长贡柑贮藏期,探究邻苯基苯酚结合果蜡涂膜处理对采后贡柑果实的保鲜效果,本研究以采后德庆贡柑果实为实验材料,研究了0.2％浓度邻苯基苯酚结合果蜡涂膜处理对采后贡柑在常温贮藏期间果实品质的影响,观察和测定了贮藏期间果实的腐烂率、硬度、可滴定酸(TA)、可溶性固形物(TSS)、维生素C(VC)、细胞膜的通透性、丙二醛(M...     

Polyphenol composition, vitamin C content and antioxidant capacity of Mauritian citrus fruit pulps

The pulp extracts of twenty-one varieties of citrus fruits (oranges, satsumah, clementine, mandarins, tangor, bergamot, lemon, tangelos, kumquat, calamondin and pamplemousses), commonly grown in Mauritius, were characterised in terms of their total soluble solids (TSS), titratable acidity (TA), polyphenol composition and vitamin C contents. Total phenolics ranged from 406.3 ± 14 to 1694 ± 19 ??g g^− 1 fresh weight (FW). Total flavonoids varied between 133 ± 6 and 965 ± 7 ??g g^− 1 FW and vitamin C contents were from 166 ± 19 ??g/mL to 677 ± 22 ??g/mL. The pulp of a pamplemousse variety had the highest TSS/TA ratio whereas lemon pulps had lowest TSS/TA ratios. The antioxidant activities of the pulp extracts were assessed and total phenolics correlated strongly with the trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant capacity (FRAP) and hypochlorous acid (HOCl) scavenging activity assays. Based on their antioxidant activities, nine citrus fruits namely, one orange, tangor, kumquat, calamondin and pamplemousse variety and two mandarin and tangelo varieties were further characterised for their flavanone, flavonol and flavone levels by HPLC. Hesperidin (6.89 ± 0.06 to 26.98 ± 0.07 mg/g FW) and narirutin (0.27 ± 0.01 and 20.91 ± 0.10 mg/g FW) were present at high concentrations compared to the other flavonoid glycosides in the pulp extracts. Naringin was detected only in pulp extracts of pamplemousses. In the light of the data obtained, citrus fruit pulps represent an important source of phytochemicals with potent antioxidant capacity.     

Effect of pulsed ultrasound treatment compared to continuous mode on microbiological and quality of Mirabelle plum during postharvest storage

The effects of pulsed and continuous ultrasound treatment on microbiological and physiological quality of Mirabelle plum fruit were investigated. Freshly harvested Mirabelle plum was treated with 30‐kHz pulsed and continuous ultrasound at 20 °C for 0, 15, 30, 45 and 60 min and subsequently stored at 4 °C for 10 days. The total count of bacteria, total fungi, decay index, titratable acidity (TA), total soluble solids (TSS), colour, texture, ascorbic acid content and total phenolics was measured. The results showed that pulsed and continuous ultrasonic treatment significantly (P < 0.05) reduced the number of microorganisms and improved the quality of Mirabelle plums during storage. Increasing pretreatment time enhanced the positive effects of pulsed and continuous ultrasound. Also, in terms of the total count of bacteria, total fungi, titratable acidity and total phenolics, the pulsed and continuous ultrasound did not show a significant difference (P < 0.05). However, pulsed ultrasound was better compared to continuous mode in preservation of TSS, colour, texture and ascorbic acid content of the fruit during storage. Our results demonstrated that pulsed ultrasound is an appropriate method for improving safety and maintaining the quality of Mirabelle plum fruit.     

Effects of nitrates and nitrites on Lactobacillus helveticus and Lactobacillus casei dairy cultures

 The aim of this work was to observe the effects of nitrites and nitrates on the titratable acidity of milk after addition of Lactobacillus helveticus (TX 121) and L. casei (CAD 154) dairy cultures and on the levels of nitrate and nitrite. After adding L. helveticus and nitrites the increasing concentrations of the latter brought about a marked decrease in titratable acidity. In milk containing 100 mg·kg^–1 nitrite the resulting concentration was 39.33 mg·kg^–1 NaNO₂. Nitrates caused a less obvious decrease in titratable acidity, giving 13.27 g·l^–1 lactic acid. In milk containing 100 mg·kg^–1 NaNO₃ the resulting concentration was 24.99 mg·kg^–1 NaNO₃. Experiments with L. casei and a nitrite additive revealed a decrease in titratable acidity to 8.89 g·l^–1 lactic acid. After incubation, nitrite levels were reduced from 100 mg·kg^–1 NaNO₂ to 37.81 mg·kg^–1 NaNO₂. Nitrates were also stated to inhibit the titratable acidity of the sample, which decreased to 11.42 g·l^–1 lactic acid. Nitrates were reduced to 46.99 mg·kg^–1 NaNO₃. The present study shows that nitrites, more than nitrates decrease the titratable acidity of milk after addition of L. helveticus and L. casei dairy cultures. A reduction of nitrates and nitrites in milk samples by Lactobacillus was also found. The results of this study can be used in the dairy industry in the production of several types of hard cheese as well as fermented milk products that use L. helveticus and L. casei dairy cultures. Received: 31 March 1999 / Revised version: 6 September 1999     

套袋对红地球葡萄果皮色素和果实品质的影响

以红地球葡萄为试材,研究了不同栽培条件下套袋对葡萄果皮花青苷、叶绿素含量及果实品质的影响。结果表明,红古地区露地栽培条件下,套袋降低了可溶性固形物、总糖、花青苷、叶绿素含量,增加了可滴定酸含量;临泽地区在设施栽培条件下套白纸袋增加了可溶性固形物、总糖、花青苷含量,降低了可滴定酸、叶绿素含量。套袋对氨基酸含量影响不大,但设施延后栽培的红地球各处理氨基酸含量均高于露地。     

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.     

Evaluation of Least Squares Support Vector Machine Regression and other Multivariate Calibrations in Determination of Internal Attributes of Tea Beverages

This research aimed to explore the relationship between internal attributes (pH and soluble solids content) of tea beverages and diffuse reflectance spectra. Three multivariate calibrations including least squares support vector machine regression (LSSVR), partial least squares (PLS), and radial basis function (RBF) neural network were adopted for development of internal attributes determination models. Ten kinds of tea beverages including green tea and black tea were selected for visible and near infrared reflectance (Vis/NIR) spectroscopy measurement from 325 to 1,075 nm. As regard the kernel function, least squares–support vector machine regression models were built with both linear and RBF kernel functions. Grid research and tenfold cross-validation procedures were adopted for optimization of LSSVR parameters. The generalization ability of LSSVR models were evaluated by adjusting the number of samples in the training set and testing set, and sensitive wavelengths that were closely correlated with the internal attributes were explored by analyzing the regression coefficients from linear LSSVR model. Excellent LSSVR models were built with r = 0.998, standard error of prediction (SEP) = 0.111, for pH and r = 0.997, SEP = 0.256, for soluble solids content, and it can be found that the LSSVR models outperformed the PLS and RBF neural network models with higher accuracy and lower error. Six individual sensitive wavelengths for pH were obtained, and the corresponding pH determination model was developed with r = 0.994, SEP = 0.173, based on these six wavelengths. The soluble solids content determination model was also developed with r = 0.977, SEP = 0.173, based on seven individual sensitive wavelengths. The above results proved that Vis/NIR spectroscopy could be used to measure the pH and soluble solids content in tea beverages nondestructively, and LSSVR was an effective arithmetic for multivariate calibration regression and sensitive wavelengths selection.     

哈姆林甜橙果实内在品质的可见-近红外光谱无损检测法

采用可见- 近红外漫反射光谱技术,结合偏最小二乘法,以不同时间采摘的哈姆林甜橙果实为样品建立其可溶性固形物、含酸量和VC 的无损检测数学模型,同时对不同光谱预处理方法和不同建模波段范围对模型的预测性能进行对比分析。结果表明：原始光谱在400～1000nm 波段的模型预测精度较高。经多元散射校正和5 点移动平均平滑预处理后,果实可溶性固形物含量的PLS 模型最好,校正集样品的相关系数为0.995RMSEC和RMSEP分别为0.026%、0.028%;预测集样品的相关系数为0.992。经多元散射校正和9 点移动平均平滑预处理后,果实含酸量的PLS 模型最好,校正集样品的相关系数为0.997,RMSEC 和RMSEP 分别为0.012%、0.013%;预测集样品的相关系数为0.997。经多元散射校正和9 点移动平均平滑预处理后,果实VC 含量的PLS 模型最好,校正集样品的相关系数为0.998,RMSEC 和RMSEP 分别为0.009%、0.009%;预测集样品的相关系数为0.999。可见由不同时间采摘的果实组成的样品集所建立的数学模型可以提高模型的预测精度,从而提高模型的适用范围。应用可见-近红外漫反射光谱检测哈姆林甜橙果实的内在品质可行。     

Application of Electronic Nose and Statistical Analysis to Predict Quality Indices of Peach

In this study, responses of a sensor array were employed to establish a quality index model able to describe the different picking date of peaches. The principal component regression (PCR) and partial least-squares regressions (PLS) model represent very good ability in describing the quality indices of the selected three sets of peaches in calibration and prediction. The results showed that the PLS model represents a good ability in predicting quality index, with high correlation coefficients (R = 0.86 for penetrating force [CF]; R = 0.83 for sugar content [SC]; R = 0.83 for pH) and relatively low standard error of prediction (SEP; 8.77 N, 0.299 °Brix, and 0.2 for CF, SC, and pH, respectively). The PCR model had high correlation coefficients (R = 0.84, 0.82, 0.78 for CF, SC, and pH, respectively) between predicted and measured values and a relatively low SEP (7.33 N, 0.44 °Brix, 0.21 for CF, SC, and pH, respectively) for prediction. These results prove that the electronic noses have the potential to assess fruit quality indices.     

Reduction of Postharvest Decay of Peach and Nectarine Caused by Monilinia laxa Using Hot Water Dipping

The effect of hot water dipping (HWD) at 40, 44 and 48 °C for 6 and 12 min on germination of conidia of brown rot fungus (Monilinia laxa) in vitro and the effect of HWD at 48 °C for 6 and 12 min on the fruit quality and development of M. laxa on peach cv. “Roig” and nectarine cv. “Venus” after artificial inoculation in cold storage were studied. Temperature and duration of treatment significantly affected germination of conidia. After HWD at 48 °C for 12 min, the lowest germination of conidia (9%) was recorded, which was more than 10 times lower than control (93%). After 3 days from inoculation, there were 80% of inoculated spots with visual symptoms of decay caused by M. laxa on control peaches and 40% of such spots on control nectarines. Successful infections were recorded on only 5% of inoculated spots of nectarine and 10% of inoculated spots of peach after HWD at 48 °C for 12 min. HWD at 48 °C for 12 min significantly decreased titratable acidity and increased soluble solids concentration/titratable acidity ratio in nectarines. No visual symptoms of heat damage were found on fruits as a consequence of any of the studied treatments. The results show that it is possible to control postharvest brown rot (M. laxa) on peach using HWD at 48 °C for 12 min and on nectarine using HWD at 48 °C for 6 min without a significant loss of fruit quality.     

Polysaccharide/Protein Nanomultilayer Coatings: Construction,Characterization and Evaluation of Their Effect on ‘Rocha’ Pear (<Emphasis Type="Italic">Pyrus communis</Emphasis> L.) Shelf-Life

Nanolayered coatings of κ-carrageenan, a polysaccharide with good gas barrier properties, and lysozyme, a protein with antimicrobial action, were in a first stage assembled on aminolysed/charged polyethylene terephthalate (PET) pieces, which acted as a support, by alternate five-layer deposition. This was performed to allow the characterization of the nanomultilayer system. PET aminolysis was confirmed by Fourier transform infrared spectroscopy and contact angle, and the subsequent layer adsorption on aminolysed PET surface was confirmed by absorbance, contact angle and SEM images. The water vapour permeability and the oxygen permeability (O₂P) of the five layers were found to be 0.013 ± 0.003 × 10⁻¹¹ and 0.1 ± 0.01 × 10⁻¹⁴ g m⁻¹ s⁻¹ Pa⁻¹, respectively. The nanomultilayer system was subsequently applied (without PET support) directly on ‘Rocha’ (Pyrus communis L.) fresh-cut pears and whole pears. Uncoated fresh-cut pears and whole pears presented higher mass loss, higher total soluble solids (TSS) and lower titratable acidity when compared with coated fresh-cut pears and whole pears. Uncoated fresh-cut pears also presented a darker colour. These results showed that the nanolayered coating assembled on the fruits’ surface has a positive effect on fruit quality and contributed to extend the shelf-life.     

Search for suitable maturation parameters to define the harvest maturity of plums (Prunus domestica L.): A case study of candied plums

Plums (Prunus domestica L.) of a greengage variety, from South–East of Portugal, are used to produce a traditional candied product, “Ameixa d’Elvas”, which has a Protected Designation of Origin, recognised by the European Union. To obtain a good texture quality in candied plums, it is necessary to define accurate maturation parameters. Parameters such as the total soluble solids (TSS), titratable acidity (TA), TSS/TA, and pH are not always suitable for this purpose. In order to find a more reliable maturation parameter, plums were collected during the commercial harvesting period, in two orchards, Vila Viçosa and Cano in different years (2003 and 2005). Total polysaccharides (PS) and uronic acids (UA) were quantified in the alcohol-insoluble residues (AIR) of pulp. In all harvests, the content of polysaccharides and uronic acids present in the AIR increased as the maturity of the fruits progressed. To the dataset that comprised the TSS, TA, TSS/TA, pH, PS, and UA measured in these plums, a linear discriminant classifier was applied to obtain a reliable parameter to predict fruit quality upon candying. The models built showed errors of lack of fitness of 0.005% for the content of UA in the AIR and 0.8% for PS, which contrasted with the errors of 17%, 21%, 17%, and 11%, for the TSS, TA, ratio TSS/TA, and pH, respectively. Considering that the variability associated with the content of PS was higher than that observed in UA estimation, and the easy and fast determination of UA, it is proposed that the UA content in AIR be used as a reliable harvesting maturity parameter, complementary to TSS and/or TA, to obtain a high quality candied product. An easy and quick laboratory methodology is proposed for the determination of the UA in plums.     

RIPENING AND QUALITY CHANGES IN MANGO FRUIT AS AFFECTED BY COATING WITH AN EDIBLE FILM

Mango fruit has a relatively short storage life of about 2 to 3 weeks at 13C. In order to prolong the storage life of ‘Haden’ mangoes, fruit were coated with 3 concentrations (8,16 and 24 g.L^?1) of the edible coating film “Semperfresh” and then stored at 13C and 85% RH. Fruit were then evaluated every 4 days for up to 32 days for total soluble solids (TSS), titratable acidity (TA), pH, firmness, weight loss, color of the skin, and ascorbic acid content. All 3 concentrations applied to the fruit affected fruit ripening. TA, firmness, and green color were higher in coated fruit, and weight loss, SST, and pH were lower compared with the noncoated fruit. “Semperfresh” had no effect on decay development. Ascorbic acid decreased in all stored fruit, but this decrease was slower in coated fruit, and there were no significant differences between the different “Semperfresh” concentrations.     

Phenolic Content and Antioxidant Activity of Moscatel Dessert Wines from the Setúbal Region in Portugal

Moscatel wines from Setúbal were analyzed for their total phenolic (mean value 1,243 mg gallic acid equivalents/L), and total flavonoid (mean value 248 mg catechin/L) composition by spectrophotometric and chromatographic methods were used to quantify phenolic compounds as benzoic acids, cinnamic acids, stilbens, and some flavonoids. Antioxidant activity of the wines was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH; mean value 70.7% inhibition), ferric reducing antioxidant power (FRAP; mean value 3,098 mg of Trolox equivalents/L) and oxygen radical absorbance capacity (ORAC; mean value 10,724 μmol/L) assays. Results were analyzed using principal component analysis which allowed samples to be grouped in terms of both winemaking producer and vintage. By plotting correlation loadings, it was possible to understand which variables were responsible for sample distribution. The correlation between results obtained for variables show that, in general, total flavonoid content is a better estimation of antioxidant activity in Moscatel samples (r _{ORAC/flavonoids} = 0.832, r _{FRAP/flavonoids} = 0.677) than total phenolic content (r _{ORAC/phenolics} = 0.680, r _{FRAP/phenolics} = 0.372). No major correlations were detected for DPPH assay results (r _{DPPH/flavonoids} = 0.283, r _{DPPH/phenolics} = 0.271). Chromatographic profiles showed important differences among Moscatel wines. Gallic acid contents and results of antioxidant activity tests were strongly correlated (r values in the range 0.74–0.92). Correlations of the results obtained for antioxidant activity tests with contents of other phenolic compounds such as ethyl caffeate, ethyl gallate, caffeic acid, protocatechuic acid, and t-caftaric acid depend on sample and type of test employed. Presented at the “AOAC Europe section international workshop: Enforcement of European Legislation on Food and Water: Analytical and Toxicological Aspects”, in Lisbon, April 2008, and published in abstract form.     

不同解冻方式对软儿梨果实品质与抗氧化物质含量的影响

冷冻和解冻是产区消费者传统上消费软儿梨的两个必要步骤,外源乙烯可以加速呼吸跃变型果实的后熟进 程。本实验以自然后熟和乙烯利催熟的软儿梨为材料,研究了传统的空气解冻和水浴解冻对解冻后果实品质和酚类 物质含量的影响。结果表明：对于自然后熟的软儿梨,空气解冻组果实的可滴定酸含量、可溶性固形物含量、固酸 比均显著高于水浴解冻组;同时使自然后熟组果实保留了更多的VC,降低了石细胞含量。空气解冻较水浴解冻降 低了乙烯利处理组果实的可滴定酸和可溶性固形物含量,但对其固酸比、VC和石细胞含量无显著影响。空气解冻 和水浴解冻均对自然后熟组果实的总酚含量无显著影响,但乙烯利处理组果实的总酚含量上升;两种解冻方式对几 种主要酚类物质的影响表现各异,但相似的是解冻后果实均不能测出绿原酸和阿魏酸。不同解冻方式对果实不同的 抗氧化指标影响各异,但从抗氧化能力综合指数来评价,不同工艺点的果实抗氧化能力依次为：水浴解冻＞空气解 冻＞后熟,在后熟和解冻中均为：乙烯利处理组果实＞自然后熟组果实。     

Mechanical parameters to assess quality changes in cherimoya fruit

 Several mechanical parameters obtained by means of compression and penetration tests, and changes in cherimoya (Annona cherimola Mill.) fruit quality during storage in air and two controlled atmospheres (CA), (3% O₂+0% CO₂ and 3% O₂+3% CO₂) were analysed. A gradient of softening was found among the equatorial and the apical areas of the flesh during CA storage, as assessed by localized penetration tests. The combination of low O₂/elevated CO₂ (3% O₂+3% CO₂) increased this gradient and had a greater inhibiting effect on skin softening than low O₂. It appeared that the prevention of softening by CA was stronger in the less mature tissues (equatorial and outer areas) than in the more mature tissues (apical and inner areas around the longitudinal axis). CA delayed or inhibited changes in fruit quality observed during air storage: increases in total soluble solids (TSS), titratable acidity (TA), and yellowness of the flesh (b), and diminution in flesh lightness of colour (L). A good relationship between an objective quality index (QI, where QI=TSS+TA+L/b) and the compression slope (CS) was found during storage under all the conditions tested. It is suggested that the relationship, QI=29.25+0.04×CS–0.0023×CS² could be useful when assessing stages of cherimoya fruit quality during storage under different conditions by performing a nondestructive, compression test.     

Mechanical parameters to assess quality changes in cherimoya fruit

 Several mechanical parameters obtained by means of compression and penetration tests, and changes in cherimoya (Annona cherimola Mill.) fruit quality during storage in air and two controlled atmospheres (CA), (3% O₂+0% CO₂ and 3% O₂+3% CO₂) were analysed. A gradient of softening was found among the equatorial and the apical areas of the flesh during CA storage, as assessed by localized penetration tests. The combination of low O₂/elevated CO₂ (3% O₂+3% CO₂) increased this gradient and had a greater inhibiting effect on skin softening than low O₂. It appeared that the prevention of softening by CA was stronger in the less mature tissues (equatorial and outer areas) than in the more mature tissues (apical and inner areas around the longitudinal axis). CA delayed or inhibited changes in fruit quality observed during air storage: increases in total soluble solids (TSS), titratable acidity (TA), and yellowness of the flesh (b), and diminution in flesh lightness of colour (L). A good relationship between an objective quality index (QI, where QI=TSS+TA+L/b) and the compression slope (CS) was found during storage under all the conditions tested. It is suggested that the relationship, QI=29.25+0.04×CS–0.0023×CS² could be useful when assessing stages of cherimoya fruit quality during storage under different conditions by performing a nondestructive, compression test. Received: 23 April 1998     

江津甜橙3 个变异品种的果实品质及酸组分分析

以江津甜橙的优选品种锦橙及其低酸变异品种长叶橙和高酸大果芽变品种大果锦橙为试材,测定果实膨大至成熟期的多项品质指标及其果汁中柠檬酸、奎宁酸和苹果酸含量的变化趋势。结果表明,在果实发育过程中,各品种果实大小于10月下旬基本定型,可溶性固形物含量逐渐增加、可滴定酸含量逐渐下降。在所测酸组分中,柠檬酸为主要有机酸;在果实发育过程中,柠檬酸含量逐渐降低,苹果酸含量呈相反的变化趋势,奎宁酸含量呈先下降后上升再下降的趋势,最大值出现在11月中旬。在果实成熟阶段,锦橙平均单果质量和柠檬酸含量介于长叶橙和大果锦橙之间,可溶性固形物含量为最高;长叶橙单果质量最小（155.27 g）,可滴定酸含量最低（0.55%）,其中柠檬酸组分含量为6.95 mg/g;大果锦橙则相反,单果质量达311.92 g,可滴定酸含量为1.02%,其中柠檬酸含量为11.72 mg/g。3 个品种总体上呈酸度越高,柠檬酸含量越高,奎宁酸含量越低的趋势。