Commercial quality, major bioactive compound content and antioxidant capacity of 12 cultivars of loquat (Eriobotrya japonica Lindl.) fruits

BACKGROUND: Modern consumers are increasingly interested in their personal health and expect the food they purchase to be tasty and attractive while being safe and healthful. The aim of this study was to determine the commercial quality, characterise the antioxidant capacity and quantify the major bioactive compounds of 12 cultivars of loquat fruits in order to establish a database for utilising these germplasm resources. RESULTS: Of the 12 cultivars, ‘Guanyu’ produced the biggest fruits, while ‘Tianzhong’ and ‘Bingtangzhong’ had the highest soluble solids content but the lowest titratable acidity. ‘Taipinghong’ was reddest in colour. Sucrose, fructose, glucose and sorbitol were the major sugars in loquat fruits, with the highest total sugar content being observed in ‘Bingtangzhong’ and ‘Tianzhong’. Phenolics and flavonoids were the main bioactive compounds and were abundant in ‘Tianzhong’ and ‘Zhaozhong’. ‘Taipinghong’ had the highest total carotenoid content, while ‘Qingzhong’ had the highest vitamin C content. ‘Tianzhong’, ‘Bingtangzhong’ and ‘Ninghaibai’ showed higher antioxidant activity than the other cultivars, as measured by assays of 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2‐azino‐bis(3‐ethylbenzthiozoline‐6‐sulfonic acid) (ABTS) scavenging and ferric‐reducing/antioxidant power (FRAP). CONCLUSION: Commercial fruit quality, major bioactive compound content and antioxidant capacity varied greatly among the 12 cultivars. ‘Bingtangzhong’ and ‘Tianzhong’ were the highest‐ranking cultivars based on their good commercial quality and high nutritional value. The loquat fruits with higher total phenolic and flavonoid contents also had clearly higher antioxidant capacities. Copyright © 2011 Society of Chemical Industry     

Acetylsalicylic acid alleviates chilling injury of postharvest loquat (Eriobotrya japonica Lindl.) fruit

Loquat (Eriobotrya japonica Lindl. cv. Luoyangqing) is a chilling-sensitive fruit and therefore has a limited postharvest life. While fruit stored at 5 °C retained its acceptable quality after 39 days, fruit stored at 0 °C had chilling injury with the symptoms of tissue browning and lignification, decrease in percentage juice, increase in superoxide free radical production, electric conductivity and lignification enzyme activities, including phenylalanine ammonia lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), and guaiacol-peroxidase (G-POD). Such chilling injury symptoms became more severe after fruit were moved to 20 °C shelf life. A postharvest application of 1 mmol/L aqueous acetylsalicylic acid (ASA, a derivative of salicylic acid) to loquat fruit significantly alleviated chilling injury symptoms, inhibited accumulation of superoxide free radical, and reduced PAL, CAD, and G-POD activities. ASA treatment impairing the accumulation of superoxide free radical may prevent chilling injury and lignification in loquat.     

枇杷花系统溶剂提取物抑菌作用研究

研究枇杷花系统溶剂提取物抑菌的作用。实验以苯甲酸钠为对照组,分别研究了枇杷花石油醚、氯仿、乙酸乙酯、正丁醇、丙酮、95%乙醇和水的提取物对大肠杆菌、金黄色葡萄球菌、白色念珠菌的抑菌效果,并对不同提取物进行薄层色谱分析。结果表明,枇杷花的提取液对细菌、真菌均有抑制作用,并优于对照组。正丁醇、丙酮提取物对金黄色葡萄球菌抑制能力优于其他溶剂;石油醚提取物对大肠杆菌抑制能力优于其他溶剂;石油醚、乙酸乙酯提取物对白色念珠菌抑制能力优于其他溶剂。     

Antioxidant Activity of Loquat (Eriobotrya japonica Lindl.) Fruit Peel and Pulp Extracts in Stabilization of Soybean Oil During Storage Conditions

The antioxidation activities of Eriobotrya japonica (Lindl.) fruit peel and pulp extracts were determined using DPPH, β-carotene, and Rancimat methods. Results showed that ethanol-water extract of peel and ethanol extract of pulp had the highest antioxidant activity. Protective effects of extracts in stabilization of soybean oil were tested and compared to tert-butyl hydroquinone by measuring peroxide values, free fatty acids, thiobarbituric acid, oxidative stability, and conjugated dienes and trienes values during storage (65 days at 25°C). Results showed that the ethanol-water extract of peel at 400 ppm exhibited stronger antioxidant activity, but the highest effect was observed in tert-butyl hydroquinone.     

Effect of Natural Extracted Antioxidants from Eriobotrya japonica (Lindl.) Fruit Skin on Thermo Oxidative Stability of Soybean Oil During Deep Frying

The effects of ultrasound-assisted, supercritical CO₂ and solvent extraction techniques on antioxidant activity of Eriobotrya japonica (Lindl.) skin extracts were investigated using 2, 2-diphenyl-1-picrylhydrazyl, β-carotene, and Rancimat assays. Solvent extract of skin at 400 ppm had the highest antioxidant activity. Solvent extraction was the most effective method on extraction of phenols and tocopherols. Protective effects of extracts in stabilization of soybean oil during frying were determined by measuring its peroxide value, total polar compounds, carbonyl value, free fatty acids, conjugated dienes, and trienes. Results indicated that solvent extract of skin at 400 ppm exhibited stronger antioxidant activity in oil than tertiary butylhydroquinone.     

枇杷花薄荷饮料的研制

以枇杷花、薄荷为原料,配以白砂糖、柠檬酸,制作清香爽口的健康饮料。通过正交试验确定其配方为枇杷花汁60%、薄荷汁4%、白砂糖9%、柠檬酸0.2%。     

Comparison of phenolic compound contents and antioxidant capacities of loquat (Eriobotrya japonica Lindl.) fruits

The characteristics, phenolic compound contants, and antioxidant capacities of 6 cultivars of loquat fruit grown in China were evaluated. HPLC was used to identify and quantify phenolics. Chlorogenic acid, neochlorogenic acid, 4-O-caffeoylquinic acid, protocatechuic acid, 4-hydroxybenzoic acid, caffeic acid, ferulic acid, ellagic acid, and o-coumaric acid were the main phenolic compounds of mature loquat fruits. Contents of chlorogenic acid, neochlorogenic acid, 4-hydroxybenzoic acid, protocatechuic acid, and o-coumaric acid were all significantly correlated with antioxidant capacities determined using DPPH, ABTS radical scavenging activity, and ferric reducing/antioxidant power assays. The ‘Taxiahong’ cultivar contained the highest amounts of total phenolics and flavonoids and the highest antioxidant capacity, while ‘Taipingbai’ showed the lowest. The high level of phenolic compounds and antioxidant capacities of some cultivars indicates that these cultivars can be sources of bioactive compounds that are relevant to human health.     

超声波辅助提取枇杷花黄酮类化合物工艺的优化

研究超声波辅助乙醇浸提法从枇杷花中提取黄酮类化合物的工艺。通过单因素试验确定了影响黄酮类化合物的主要因素及较优水平,用正交试验优化提取工艺条件。结果表明,最佳工艺为:超声波功率为250 W,乙醇体积分数60%,提取温度60℃,提取时间40 min,料液比1︰20。最佳条件下枇杷花黄酮类化合物含量为83.7 mg/g。     

Determination of organic acids and sugars in loquat (Eriobotrya japonica Lindl.) by high-pressure liquid chromatography

The major sugars and organic acids in three cultivars of loquat-Tanaka, Thales and Christmas-were quantified by high-pressure liquid chromatography. The cultivars differed in sugar and acid contents and changes in these contents during ripening were determined for one cultivar. Trace quantities of several unknown acids that had not been reported earlier in loquat were observed in the Tanaka sample. Major B-vitamins, thiamin, riboflavin and niacin, were quantified for one cultivar and were at the approximate levels found in other fruit.     

Postharvest biology and technology of pomegranate

Pomegranate is a subtropical and tropical fruit of great importance from a health point of view. Despite increasing consumer awareness of the health benefits of pomegranate, consumption of the fruit is still limited owing to poor postharvest handling, storage recommendations, short shelf life and quality deterioration during transportation, storage and marketing. The occurrence of physiological disorders such as husk scald, splitting and chilling injury is another challenge reducing marketability and consumer acceptance. Recently, notable work on postharvest biology and technology has been done. Pomegranate is highly sensitive to low‐oxygen (<5 kPa) atmospheres, chilling injury and decay. One of the major problems associated with pomegranate fruit is excessive weight loss, which may result in hardening of the husk and browning of the rind and arils. To reduce chilling injury incidence and to extend storability and marketing of pomegranates, good results were obtained with polyamine, heat, salicylic acid, methyl jasmonate or methyl salicylate treatments prior to cold storage. This article reviews the maturity indices, changes during maturation and ripening, postharvest physiology and technology of pomegranate fruit as well as the various postharvest treatments for maintaining fruit quality. © 2015 Society of Chemical Industry     

响应面法优化枇杷叶中科罗索酸超声提取工艺

研究枇杷叶中科罗索酸超声提取最佳工艺条件。在单因素试验的基础上,选定甲醇体积分数、料液比和时间作为影响因素,以科罗索酸提取率为评价指标。通过3因素3水平Box-Behnken中心组合试验,建立科罗索酸提取率的二次多项式回归方程,经响应面回归分析得到优化组合条件。结果表明,超声波法提取枇杷叶中科罗索酸的最佳工艺条件为:甲醇体积分数87.8%,料液比1:26(g/mL),超声时间34min。枇杷叶中科罗索酸的一次实际提取率可达0.525%,与理论预测值吻合较好,说明该优化方法可行。     

Volatile Constituents of Loquat (Eriobotrya japonica Lindl.) Fruit

Concentrates of fresh, ripe Spanish loquat fruit were analyzed by HRGC, HRGC-MS and HRGC-FTIR. In total, 80 aroma substances were identified, of which 72 are reported for the first time as loquat fruit constituents. The major part of volatiles comprised alcohols and carbonyls. Quantitative HRGC revealed hexanal (2.4 mg/kg fruit pulp), (E)-2-hexenal (1.8 mg/kg) and benzaldehyde (0.7 mg/kg) as major aroma compounds.     

Volatile Constituents of Loquat (Eriobotrya japonica Lindl.) Fruit

Eighteen volatile compounds have been identified in a methylene chloride extract of a distilled fraction from loquat fruit. Individual compounds were identified by comparison of gas chromatographic retention times and mass spectra with those for authentic compounds. Major components phenyl ethyl alcohol, 3-hydroxy-2-butanone, phenylacetaldehyde and hexen-1-ols, and minor components, ethyl acetate, methyl cinnamate and β-ionone probably contribute to the fruity-floral flavor of the fruit.     

枇杷花三萜化合物提取工艺

目的：研究枇杷花三萜类成分熊果酸、齐墩果酸最佳工艺条件。 方法：采用反相高效液相法同时测定熊果酸、齐墩果酸含量,应用单因素及 L9(34)正交试验得到提取枇杷花中三萜类化合物的最佳工艺。 结果：确定最佳工艺条件为95% 乙醇10 倍量体积在80℃下提取1 次,每次2h。结论：本实验采用的方法和指标适合于枇杷花的提取,为将其开发成为现代中药成方制剂提供科学依据。     

分光光度法测定枇杷叶总三萜物质含量

采用分光光度法对枇杷叶中总三萜物质含量进行测定.结果表明:φ(香草醛-冰醋酸)=5%溶液0.3 mL,高氯酸1.0 mL,60℃水浴15 min,冰浴冷却,加冰醋酸5.0 mL摇匀,在542 nm处测定,其效果最佳.标准曲线方程y=0.0044x 0.0012(r=0.9994),线性范围在100.00μg/L~1000.00μg/L,回收率为95.47%~99.76%.该方法简便快速,灵敏度高,重现性好.     

Use of UV-C treatments to maintain quality and extend the shelf life of green fresh-cut bell pepper (Capsicum annuum L.)

Abstract: The objective of this work was to select a Ultraviolet‐C (UV‐C) treatment for fresh‐cut mature green bell pepper, and to evaluate the effect of its combination with refrigeration on quality maintenance. Bell pepper sticks were treated with 0, 3, 10, or 20 kJ/m² UV‐C in the outer (O), inner (I), or both sides of the pericarp (I/O) and stored for 8 d at 10 °C. During the first 5 d of storage, all UV‐C treatments reduced deterioration as compared to the control. The treatment with 20 kJ/m² I/O was the most effective to reduce deterioration, and was used for further evaluations. In a second group of experiments, mature green bell pepper sticks were treated with 20 kJ/m² I/O, stored at 5 °C for 7 or 12 d and assessed for physical and chemical analysis, and microbiological quality. UV‐C‐treated fruit showed lower exudates and shriveling than the control. UV exposure also reduced decay, tissue damage, and electrolyte leakage. After 12 d at 5 °C, UV‐C irradiated peppers remained firmer and had higher resistance to deformation than the control. The UV‐C treatments also reduced weight loss and pectin solubilization. UV‐C exposure decreased the counts of mesophile bacteria and molds, and did not affect acidity or sugars. UV‐C‐treated fruit stored for 0 or 7 d at 5 °C did not show major differences in antioxidants from the control as measured against DPPH^? or ABTS^?+ radicals. Results suggest that UV‐C exposure is useful to maintain quality of refrigerated fresh‐cut green pepper. Practical Application: Exposure to UV‐C radiation before packing and refrigeration could be a useful nonchemical alternative to maintain quality and reduce postharvest losses in the fresh‐cut industry.     

枇杷叶中熊果酸的提取工艺研究

对超声波辅助提取枇杷叶中的熊果酸进行较为系统的研究。选择乙醇体积分数、提取时间、液固比、提取次数、物料的粒子大小5 个影响因素,运用均匀设计法安排实验,以高效液相色谱测定熊果酸的含量。以提取率为实验指标,用自主提出的可视分析方法对多维空间实验数据进行分析,并且以20 倍原料量进行了尚佳工艺放大实验。最终确定最佳工艺范围为乙醇体积分数80%～100%、提取时间50～65min 和80～100min,提取次数1 次。此类提取中,液固比和物料的粒子大小对提取率影响复杂。     

采后硅酸钠处理对杏果黑斑病的控制及品质的影响

研究了采后硅酸钠处理对杏果黑斑病的控制及品质的影响。结果表明:体外条件下不同浓度硅酸钠对黑斑病病原物Alternaria alternata的生长具有显著的抑制作用,其中以25mmol/L处理效果最好,抑菌率可达72.73%。50mmol/L硅酸钠浸泡可明显降低杏果损伤接种A.alternata的病斑直径,处理组病斑直径低于对照22%,且抑制效果可持续96h。50mmol/L硅酸钠处理还有效延缓了常温贮藏初期果实硬度的下降,维持了较高的可滴定酸和VC的含量,但对可溶性固形物含量无明显影响。由此表明,采后硅酸钠处理可通过直接抑菌和诱导果实抗性来控制杏果黑斑病,并在一定程度上维持果实的品质。     

枇杷叶黄酮提取物的抗氧化作用研究

分别研究枇杷叶不同部位提取物中黄酮含量及黄酮提取物的抗氧化活性。采用超声法分别提取枇杷叶不同部位的黄酮类物质,用比色法测定含量。采用Schaal烘箱法,以过氧化值为指标研究了黄酮提取物对猪油的抗氧化效应,并采用DPPH自由基和ABTS自由基清除体系评价总黄酮的抗氧化能力。结果表明:枇杷叶尖部位的黄酮含量最高为(5.79±0.03)mg/g。在所研究的浓度范围内,枇杷叶黄酮对猪油具有一定的抗氧化作用,且随着其剂量的增加而增强;枇杷叶黄酮对DPPH自由基和ABTS自由基都具有较强的清除能力,在一定浓度范围内,清除自由基能力与浓度存在量效关系。