Influence of ripening and astringency on carotenoid content of high-pressure treated persimmon fruit (Diospyros kaki L.)

Rojo Brillante is an astringent variety of persimmon fruit that needs a de-astringency treatment (95% CO₂/20 °C/24 h) before commercialisation to improve its sensorial quality. This fruit is a good source of bioactive compounds, such as carotenoids. Effects of high-pressure processing (HPP) (200–400 MPa/25 °C/1–6 min) on carotenoid content of astringent and non-astringent persimmon fruits at two maturity stages (III and V) were studied. With regard to control samples, non-astringent fruits at maturity stage V, showed the highest carotenoid content and vitamin A value. In general, HPP at 200 MPa produced a statistically significant increase in extracted carotenoid content for astringent samples (up to 86% and 45% at maturity stages III and V, respectively), whereas no significant differences or even a decrease was observed for non-astringent ones or those treated at 400 MPa. HPP of astringent persimmon fruit at 200 MPa/25 °C/6 min showed the best result in terms of carotenoid extractability. Therefore, HPP could be a useful tool to produce an improvement on the extraction of potentially health-related compounds and, in consequence, to modify their bioaccessibility.     

Incidence and growth of Listeria monocytogenes in persimmon (Diospyros kaki) fruit

The incidence of Listeria monocytogenes on persimmon (Diospyros kaki) surface of 'Fuyu' and 'Rama Forte' was evaluated during a 5-month-period (from March to July) of two seasons periods (years 2005 and 2006). The fruits were collected in wholesale and street markets and retail in Sao Paulo and Campinas City, Brazil. A total of 582 fruits were analyzed using the Bax System which is based on the Polymerase Chain Reaction. The ability of this pathogen to grow on the peel and pulp of the two persimmon varieties was also verified at different incubation periods at the temperatures of 10, 20 and 30 degrees C. The growth parameters were obtained by modeling the experimental data using the Gompertz function. The incidence survey showed the absence of L. monocytogenes. The growth curves showed that L. monocytogenes can grow on the peel as well as in the pulp of the two persimmon varieties studied incubated at 10, 20 and 30 degrees C and that low temperatures can reduce the generation rate but does not inhibit its growth.     

Cholesterol-lowering effect of astringent persimmon fruits (Diospyros kaki Thunb.) extracts

Food Science and Biotechnology - This study aimed to investigate the effects of ethanol extract of astringent persimmon on antioxidant activity, cholesterol, 3-hydroxy-3-methylglutaryl (HMG)-CoA...     

Antioxidant properties of Korean major persimmon (Diospyros kaki) leaves

Food Science and Biotechnology - Persimmon is one of the most common native fruits of South Korea and its leaves are well known to be used in pharmaceuticals, cosmetics as well as beverages. The...     

Purification and characterisation of two pectinmethylesterase from persimmon (Diospyros kaki)

Two pectinmethylesterase isoforms, PME I and PME II, have been separated and purified from persimmon using chromatography techniques. Both isoforms presented differences in molecular weight (PME I: 51 kDa, PME II: 30 kDa), isoelectric point (PME I: 8·4, PME II: 6·9) and K_m values (PME I: 54 μg ml⁻¹, PME II: 31 μg ml⁻¹). They differed in their optimum pH and thermal stability, PME I being the more thermostable isoform. Both isoforms exhibited similar behaviour with respect to Ca²⁺ and Na⁺ concentrations and were strongly inhibited by CaCl₂ concentrations of over 80 mM and by NaCl concentrations of over 500 mM . Both isoforms were activated by low concentrations of polygalacturonic acid and were competitively inhibited by D -galacturonic acid and high concentrations of polygalacturonic acid. ©1997 SCI     

Solvent effects on antioxidant properties of persimmon (Diospyros kaki L. cv. Daebong) seeds

The aim of this study was to investigate the antioxidant activities of persimmon seed extracts (PSE) using different solvents such as ethanol, methanol, acetone, and their aqueous 80% solvents. The EC₅₀ values of the extracts from absolute ethanol (EE) and methanol (ME) in 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical–scavenging assay were 49.71 and 51.15 μg mL^?1, respectively, while the EC₅₀ of butylated hydroxyanisole (BHA) was 70.82 μg mL^?1. However, the EC₅₀ value of reducing power for the absolute acetone extract (AE) was higher (210.06 μg mL^?1) than that of BHA (212.67 μg mL^?1). Although the absolute ME had the highest antioxidant activity, it exhibited the lowest total phenolics and flavonoids. In contrast, the antioxidant activities of the aqueous solvent extracts showed a good correlation with total phenolics and flavonoids when compared to the absolute solvent extracts. The results showed that PSE could potentially be used as an inexpensive source of natural antioxidant in food and pharmaceutical industries.     

Radical scavenging activity and phenolic compounds in persimmon (Diospyros kaki L. cv. Mopan)

ABSTRACT:  The Mopan persimmon ( Diospyros kaki L. cv. Mopan) is the major cultivar of astringent persimmon in northern China. This study investigates the radical scavenging activity against ABTS and DPPH radical, and the content of total and individual phenolics (catechin, epicatechin, epigallocatechin, chlorogenic acid, caffeic acid, and gallic acid) with apple, grape, and tomato as controls. The radical scavenging activities against ABTS and DPPH radicals of the Mopan persimmon are 23.575 and 22.597 μm trolox eq/g f.w., respectively. These findings suggest that the Mopan persimmon's antioxidant activity is significantly ( P < 0.05) stronger than that of reference materials. The Mopan persimmon showed the highest content of total phenolics among the 4 materials tested. Significant correlations ( R ²= 0.993, P < 0.05, ABTS radical; R ²= 0.980, P < 0.05, DPPH radical) are found between the total phenolics and the radical scavenging activities. The total content of these 6 kinds of phenolics (catechin, epicatechin, epigallocatechin, chlorogenic acid, caffeic acid, and gallic acid) is significantly correlated ( R ²= 0.831, P < 0.05, ABTS radical; R ²= 0.745, P < 0.05, DPPH radical) with the individual radical scavenging activity of the 4 materials, although the total content of the 6 phenolics accounts for no more than 20% of the total phenolics in the Mopan persimmon. Gallic acid exhibits the strongest antioxidant activity in all 6 kinds of phenolics and its content is the largest in the Mopan persimmon, presumably being responsible for its much higher antioxidant activity as compared to apple, grape, and tomato.     

柿子单宁优化提取工艺探讨

探讨了柿子果肉中总酚和缩合单宁的优化提取工艺,采用Folin-Denis法和改良的香草醛-盐酸法分别进行总酚和缩合单宁含量的测定。通过正交实验确立了含1%盐酸的无水甲醇是最佳提取溶剂,提取最佳条件为提取时间40min、提取温度90℃、料液比1∶12、提取3次。     

Extending shelf-life of persimmon (<Emphasis Type="Italic">Diospyros kaki</Emphasis> L.) fruit by hot air treatment

‘Qiandaowuhe’ persimmon fruits (Diospyros kaki L.) were stored at 20 °C after exposed to 20 °C (control), 44 °C (T ₄₄), 48 °C (T ₄₈) or 52 °C (T ₅₂) hot air for 3 h, respectively. Firmness, weight loss, peel color, total carotenoids content, soluble solids content (SSC), titratable acidity (TA), respiration, and ethylene production and cell wall hydrolysis enzymes activities were monitored to determine the efficacy of hot air treatment in delaying persimmon fruit ripening. Results showed that ‘Qiandaowuhe’ persimmon fruit displayed a typical climacteric pattern of respiration and ethylene production. Peak of CO₂ and ethylene production was observed after 4 days. Fruit softening was accompanied by a progressive increase in weight loss, total carotenoids content and decrease in h°. The activities of pectinmethylesterase (PME) and polygalacturonase (PG) sharply increased and reached maximal values after 4 and 6 days, respectively. Hot air treatment significantly delayed the onset of climacteric ethylene production, respiration, PME and PG activities in persimmon fruit. Moreover, it also significantly retarded the increase in carotenoids content and SSC, while decreased the firmness, h°, and TA. The hot air treatment promoted fruit weight loss. The shelf-life of persimmon ripening increased 4 days by T ₄₄, and 6 days by T ₄₈ or T ₅₂. Results suggest that hot air treatments can greatly extend the postharvest life of ‘Qiandaowuhe’ persimmon fruit.     

Dietary fibre components,antioxidant activities and hydration properties of ripe persimmon (Diospyros kaki L. cv. Daebong) peel powders as affected by different washing treatments

Dietary fibre components, hydration properties and antioxidant activities such as 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging, reducing power, metal chelating and 2,2′‐azino‐bis,3‐ethyl‐benzo‐thiazoline‐6‐sulphonic acid (ABTS) radical scavenging activities of persimmon peel powders using different washing treatments (tap water at 20 °C and hot water) were investigated. Peel powder obtained from hot water‐washed peels (74.95 g per 100 g) had higher dietary fibre content than tap water‐washed (65.50 g per 100 g) and unwashed (60.99 g per 100 g) peels. The higher content of total phenolic and ascorbic acid were found in peel powder obtained from unwashed peels, whereas washed peels had more β‐carotene content. The EC₅₀ values of scavenging DPPH and ABTS radical for peel powders obtained from unwashed, tap water‐washed and hot water‐washed peels were 75.44, 142.18 and 110.17 μg mL^?1 respectively and 5.31, 5.34 and 5.39 μg mL^?1 respectively. Therefore, hot water washing is recommended to obtain better quality products from persimmon peel for use as a fibre supplement.     

Changes in sugars, acids and fatty acids in naturally parthenocarpic date plum persimmon (Diospyros lotus L.) fruit during maturation and ripening

The date plum persimmon fruit (Diospyros lotus L., fam: Ebenaceae) is cultivated throughout northern of Turkey for its edible fruits. Sugars and organic acids were measured during fruit maturation and ripening using HPLC. The analyses showed that fructose and glucose were the main sugars accumulated in the fruit pulp. Fructose and glucose increased up to 43,552.8 mg.100 g^–1 fw and 35,450.8 mg.100 g^–1 fw respectively during fruit ripening. Sucrose content remained relatively low and decreased during ripening. The major organic acids found in date plum fruit were citric and malic acids, which increased through the immature and midripe maturity, and then the levels decreased in the overripe fruit. Palmitic acid (16:0), palmitoleic acid (16:1), stearic acid (18:0), oleic acid (18:1) and linolenic acid (18:3) were among the major fatty acids determined by GC throughout the maturation and ripening of the fruits. The levels of these fatty acids were found to be significantly different (P=0.05) between the three maturity stages. The fruits displayed the level of linoleic acid (0.7%) in low and -linolenic acid (17.8%) in higher quantities, and the combined levels of linoleic and -linolenic acid comprised 19% (120.1 g.g^–1 dw) of the total fatty acid content in the over ripened fruit. These results show that naturally parthenocarpic date plum fruits have high levels of sugars and organic acids and moderate levels of fatty acids that significantly changed during maturation and ripening. This information can be used by nutritionalists and food technologists to improve the nutrition of local people and develop food products that would be beneficial to human health.     

柿树中3种主要活性成分研究进展

本文对10多年来国内外有关柿树中黄酮类、三萜类(主要是熊果酸与齐墩果酸)及单宁类3种主要功能性化合物的分布部位、提取方法、药理作用的研究结果进行综合分析,并提出了今后的研究思路,以期为柿树资源药用价值的进一步开发利用提供理论依据。      

Effect of 1-methylcyclopropene on ripening of postharvest persimmon (Diospyros kaki L.) fruit

Postharvest persimmon fruit (Diospyros kaki L. cv. Qiandaowuhe) was stored at 20 °C after being exposed to 3 μl l⁻¹ 1-methylcyclopropene (1-MCP) for 6 h or not (control). Several parameters (firmness, respiration and ethylene production, pectic substances and cell wall hydrolysis enzymes activities) were examined to determine the efficacy of 1-MCP treatment in delaying persimmon fruit ripening. Results showed that ‘Qiandaowuhe’ persimmon fruit displayed a typical climacteric pattern of respiration and ethylene production. Peak CO₂ production and ethylene production was observed on the fourth day. Fruit softening was accompanied by a progressive increase in water-soluble pectic substances (WSP) and a progressive decrease in chelator-soluble pectic substances (CSP) and alkali-soluble pectic substances (ASP). The activities of pectinmethylesterase (PME) and polygalacturonase (PG) started increasing sharply and reached a maximal value on days 4 and 6, respectively, and then decreased slowly. 1-MCP treatment delayed the onset of climacteric ethylene production and respiration in persimmon fruit, and also significantly retarded the activities of PME and PG during ripening at 20 °C. Consistent with the activity trends of cell wall hydrolysis enzymes, 1-MCP treatment also delayed the depolymerization of CSP and ASP and reduced the increase of WSP compared with the control fruit. Thus, application of 1-MCP can greatly extend the postharvest life of ‘Qiandaowuhe’ persimmon fruit.     

HPLC法测定不同采收期的云南甜柿叶中三种黄酮的含量

利用回流提取法对不同采收期的云南甜柿叶进行预处理,采用高效液相色谱法测定样品中山奈酚-3-O-β-D-葡萄糖苷、山奈酚-3-O-β-D-半乳糖苷和槲皮素-3-O-β-D-葡萄糖苷的含量。具体方法为:提取条件为提取溶剂45%乙醇,液固比20∶1,提取4次,提取时间90 min;液相色谱条件为采用ZORBAX Eclipse XDB-C₁₈（250 mm×4.6 mm,5μm）色谱柱分离,甲醇-0.4%磷酸溶液为洗脱系统进行梯度洗脱,检测波长265 nm;三种黄酮的相对标准偏差均小于1%,平均回收率均在99%以上。该方法具有较好的分离效果和较高的稳定性,适用于用来分析不同采收期的云南甜柿叶中上述三种黄酮的含量,测定结果表明三种黄酮在叶中积累具有规律性,随柿果实成长不断积累,并且果实成熟时达到最高。      

The effects of temperature and pH on the extraction of oxalate and pectin from green kiwifruit (Actinidia deliciosa L.), golden kiwifruit (Actinidia chinensis L.), kiwiberry (Actinidia arguta) and persimmon (Diospyros kaki)

Oxalates and pectin were extracted from four locally grown fruits at three different pH levels, 6.9, 0.6 and ?0.3, at two different temperatures, 21 and 80 °C. Green kiwifruit (Actinidia deliciosa L. Hayward), golden kiwifruit (Actinidia chinensis L. Hort 16A Zespri), kiwiberry (Actinidia arguta, CV. Takaka Green) and persimmon (Diospyros kaki) contained moderate levels of oxalates. Total and soluble oxalates were more efficiently extracted at 21 °C using 2 m HCL, while the highest amounts of pectin were extracted from the fruits at 80 °C using 0.2 m HCL. Extraction using 0.2 and 2 m HCL gave the highest yields of total oxalates, which ranged from 47.1 to 220.4 mg total oxalates per 100 g dry matter (DM) for persimmon and kiwiberry, respectively. Extraction using water at 21 °C gave soluble oxalate contents ranging from 21.2 mg 100 g^?1 DM, for persimmon, to 105.0 mg 100^?1 DM, for kiwiberry fruits. Extraction of pectin was not achieved efficiently using water at either temperature, while extraction using 2 m HCL gave lower values; optimal extractions of pectin were achieved at 80 °C using 0.2 m HCL.