The influence of ripening stage and cultivation system on the total antioxidant activity and total phenolic compounds of yellow passion fruit pulp

BACKGROUND: This work aimed to investigate the influence of both ripening stage and cultivation system on the total phenolic compounds (TPC) and total antioxidant activity (TAA) of passion fruit pulp. TPC extraction was optimized using a 2³ central composed design. The variables were fruit pulp volume, methanol volume and extraction solution volume. TPC was determined using the Folin–Ciocalteu reaction, and TAA using the ABTS radical reaction. RESULTS: The conditions to extract TPC were 2 mL passion fruit pulp and 9 mL extraction solution containing 40% methanol:water (v/v). TPC values increased in the passion fruit pulp during ripening for both cultivation systems, ranging from 281.8 to 361.9 mg gallic acid L^?1 (P?0.05) for the organic pulp and from 291.0 to 338.6 mg gallic acid L^?1 (P?0.05) for the conventional pulp. CONCLUSION: TPC values increased during ripening for both organic and conventional passion fruit. The same was true for TAA values for conventional passion fruit. For organic passion fruit, however, TAA values were highest at the initial ripening stages. These results suggest that antioxidant compounds exert strong influence on the initial ripening stages for organic passion fruit, when TPC still did not reach its maximum level. Copyright © 2012 Society of Chemical Industry     

Post-harvest changes in some volatile flavour constituents of yellow passion fruit (Passiflora edulis f. flavicarpa)

The yellow passion fruit (Passiflora edulis f. flavicarpa) was stored after harvest at ambient temperature (29 ± 2°C). Volatile flavour components were analysed up to a period of 15 days using a headspace technique combined with high-resolution gas chromatography and mass spectrometry. Several compounds–ethyl butanoate, hexyl butanoate, ethyl hexanoate, ethyl acetate, 2-heptanone, benzaldehyde and 1-hexanol–were quantitatively monitored during post-harvest storage of fruit.     

干燥方式对百香果皮理化、功能及抗氧化特性的影响

目的：探讨干燥方式对百香果皮的影响。方法：分别采用微波真空冷冻干燥、真空冷冻干燥、热泵干燥和远红外辐射干燥处理百香果皮,并分别测定其干燥特性、复水比、色差、膳食纤维、功能特性、微观结构、总酚含量、总黄酮含量及抗氧化性等指标。结果：热泵干燥百香果皮复水比、功能特性等较差;与远红外辐射干燥相比,微波真空冷冻干燥缩短了53%的干燥时间,且微波真空冷冻干燥处理的百香果皮具有较高的复水比（7.45）、总酚含量（13.45 mg GAE/g DW）和抗氧化活性（DPPH自由基清除率为38.53%,FRAP为1.14 mmol/L）;真空冷冻干燥处理的百香果皮获得了较高的持水力[（21.64±0.21） g/g]、持油力[（6.09±0.71） g/g]、溶胀性[（25.00±1.00） g/g],以及更高的总黄酮含量（7.84 mg RT/g DW）;经不同方式干燥后果皮的复水比、膳食纤维、功能特性、总酚含量、总黄酮含量、抗氧化活性等存在显著性差异（P＜0.05）。结论：干燥方式对百香果皮品质具有显著影响,其中微波真空冷冻干燥是较佳干燥方式。     

Effects of fibre derived from passion fruit seed on the activities of ileum mucosal enzymes and colonic bacterial enzymes in hamsters

Passion fruit, a popular tropical fruit, produces a large quantity of edible seeds as agricultural byproducts after juice extraction. The defatted passion fruit seed (PFS) contained a high level of insoluble fibre (∼90%, w/w) of desirable characteristics and physicochemical properties. Cellulose, pectic substances and hemicellulose were the major structural polysaccharides of the PFS insoluble fibre. In this study, the influence of the PFS insoluble fibre on the activities of ileum mucosal enzymes and colonic bacterial enzymes was investigated. It was found that the incorporation of the PFS insoluble fibre into a fibre‐free diet at 5% level significantly (p < 0.05) enhanced the intestinal amylase activity (137%), reduced the caecal pH (6.22), decreased the caecal ammonia content (−38.6%) and faecal ammonia output (−21.2%), and also decreased the activities of β‐D ‐glucosidase (−37.4%), β‐D ‐glucuronidase (−52.9%), mucinase (−35.5%) and urease (−91.4%) in faeces. Our results suggested that PFS insoluble fibre might exert favourable effects on intestinal health. The fact that PFS insoluble fibre was more effective than cellulose in improving intestinal health suggested it could be exploited as a new functional ingredient to promote intestinal function and health. Copyright © 2005 Society of Chemical Industry     

国产三效板式蒸发器在浓缩果汁生产中的应用

介绍了国产三效板式蒸发器成功替代进口蒸发器及其在浓缩果汁生产中的应用     

Use of honey bees (Apis mellifera L.) to detect the presence of Mediterranean fruit fly (Ceratitis capitata Wiedemann) larvae in Valencia oranges

BACKGROUND: When fruit deteriorates a characteristic profile of volatile chemicals is produced that is different from that produced by healthy fruits. The identification of such chemicals allows the possibility of monitoring the fruit for early signs of deterioration with biological sensors. The use of honey bees and other insects as biological sensors is well known. This study aimed to identify the volatiles produced by oranges infested with larvae of the Mediterranean fruit fly and to test the ability of honey bees, conditioned to this volatile chemical profile, to detect such oranges. RESULTS: Seventeen compounds that were present in higher concentrations in the volatile profiles of infested oranges than in those of insect‐free fruits were mixed at the same relative concentrations as those in the collected volatiles of infested oranges. The synthetic mixture was used to train honey bees by classical Pavlovian conditioning and subsequent tests showed that they were then able to discriminate between medfly‐infested and uninfested oranges. CONCLUSION: This study demonstrates an innovative way of detecting, at an early stage, the symptoms of damage to oranges by the Mediterranean fruit fly. Copyright © 2012 Society of Chemical Industry     

Influence of jam processing upon the contents of phenolics,organic acids and free amino acids in quince fruit (<Emphasis Type="Italic">Cydonia oblonga</Emphasis> Miller)

Phenolic compounds, organic acids and free amino acids of quince were evaluated, before and after jam processing, to test the effect of thermal processing in these compounds. In addition, the composition of jams prepared with peeled and unpeeled quinces was compared. Phenolics, organic acids and free amino acids were analysed by HPLC/DAD, HPLC/UV and GC/FID, respectively.