Betacyanins in dragon fruit peels: the kinetic models of their degradation under different treatment conditions

In this study, after purification, the content of betacyanins in dragon fruit peels was 9.22 mg g⁻¹ dry sample. The stability of betacyanins under the effect of different concentration of metal cation (K⁺, Na⁺, Cu²⁺, Fe²⁺, Fe³⁺, Mg²⁺, Al³⁺) solutions and sugars (glucose, sucrose, fructose, maltose and lactose) solutions was observed. The results showed that 10% lactose and 0.08 mol L⁻¹ potassium chloride solution increased the stability of betacyanins and could be used as stabiliser agents. The degradation reaction under different temperatures (20, 30, 40, 50, 60, 70, 80 °C), pH (2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0) and light conditions (light and dark) of mixed solution (betacyanins and stabiliser), including aqueous pigments solution (APS), lactose pigments solution (LPS) and potassium chloride pigments solution (PCPS), accorded with the first-order reaction kinetics. The t_1/2 values (the hours needed for 50.0% degradation of betacyanins) of LPS even up to 330.0 h at 20 °C and dark condition.     

采后果实链格孢属真菌病害防治方法研究进展

链格孢属真菌(Alternaria spp.)可引起多种果实采后发生病害,每年造成的损失异常严重,因此防治由链格孢属真菌引起的采后果实病害显得尤为迫切。文章将着重介绍国内外研究中采后果实链格孢属真菌病害的防治方法,包括采前防治,采后物理、化学和生物方法及联合防治等,并提出在未来的发展中应该使用新的、有效的组合方式来提高防治效果,增强果实抵抗链格孢属真菌的能力,延长果实采后贮藏期,提升其商品价值。     

Effect of a cold‐active pectinolytic system on colour development of Malbec red wines elaborated at low temperature

The effect of a new cold‐active pectinolytic system on colour of Malbec wines was studied under the following winemaking conditions: (i) fermentation at low temperature (20 °C) and (ii) prefermentative cold maceration (PCM) (5 °C–7 days) followed by traditional fermentation (28 °C). The pectinolytic system was mainly composed of polymethylgalacturonase and pectin lyase activities, detected under similar conditions to those in winemaking (pH 3.6–20 °C). The results show that the enzyme system significantly accelerated colour extraction by reducing the maceration time necessary for vinification at low temperature and shortening the PCM stage. Enzyme‐treated wines exhibited better chromatic parameters than their controls at devatting and after 6 months of storage. The cold‐active enzyme compensated the decrease in colour extraction due to the low maceration temperature, achieving high‐quality wines with chromatic characteristics similar to those of traditional wines.     

Grape seed removal: effect on phenolics,chromatic and organoleptic characteristics of red wine

Winemakers are interested in wines with low bitterness and astringency, and therefore, there is a preference for a higher presence of skin proanthocyanidins in wines. However, the information regarding the effect of reducing or eliminating seed proanthocyanidins from the must or fermenting wine on the characteristics of finished wines is scarce. For this reason, we elaborated a wine using Monastrell grapes from which the seeds had been removed and compared it with a control wine (CW) made from intact grapes. The anthocyanin and proanthocyanidin concentration and profile, and the chromatic and sensory characteristics were studied. The absence of seed proanthocyanidins did not affect anthocyanin concentration, although the proanthocyanidin concentration was 40% lower than in the CW. The copigmentation (CA) study showed that both wines had a similar extent of CA phenomena although colour intensity was higher when seed proanthocyanidins were present. The panellist evaluated the wines elaborated without seeds as being fruitier, less astringent and with an overall higher quality.     

Effects of hydrogen sulphide on quality and antioxidant capacity of mulberry fruit

Here we investigated the effect of hydrogen sulphide (H₂S) on postharvest quality of mulberry fruit and possible underlying mechanisms. Endogenous H₂S content first increased after harvest and then decreased sharply with the process of ripening and senescence. A fumigation with H₂S released from 0.8 mm NaHS solution could significantly enhance the endogenous H₂S content by increasing the activities of D‐cysteine desulfhydrase and L‐cysteine desulfhydrase. NaHS could significantly slow down the ripening rate of mulberry fruit and reduce the respiratory intensity and anthocyanin content. Moreover, H₂S fumigation was able to obviously delay or slow down the decreases in soluble protein, titratable acidity and ascorbate contents. Further results showed that activities of representative antioxidant enzymes in H₂S‐treated sample were higher than those of control samples during storage, resulting in a decrease in superoxide anion production. Together, these results clearly indicate that H₂S fumigation has a potential role in the preservation of mulberries.     

The role of acidity,sweetness, tannin and consumer knowledge on wine and food match perceptions

The purposes of this study were to (1) explore significant differences in perception of match for a variety of food and wine styles; (2) evaluate the impacts of wine sweetness level, wine acidity level, and wine tannin level on perception of match; and (3) investigate the impact of food and wine expertise on perceived level of match. The highest perceived wine matches for each food item were: Sauvignon Blanc and chêvre, Chardonnay and brie, Cabernet Sauvignon and spicy Italian salami, and Port and milk chocolate. Wine sweetness, acidity, and tannin levels all significantly impacted the level of match with certain food items. Food and wine expertise also significantly impacted the level of match, indicating differences between the more expert and novice participants in the role wine sweetness, acidity, and tannin had on level of match.     

Training realisation and training demand in the Rioja wine sector in Spain

Training has been identified as an effective tool in the development of human resources, especially in the current context of change. This work aims to analyse the realisation and demand on training courses in the Rioja wine sector in Spain. A representative sample of companies in the sector was interviewed using a questionnaire. Two types of analysis were conducted: univariate and a factorial analysis of variance. These analyses allow using a hypothesis test in which three independent variables are controlled – zone, ownership, and winery size. The results show that the realisation and demand for training are focused on topics related to wine production, and not on marketing. No significant differences were found regarding the realisation and demand for training and the independent variables.     

果品分级检测技术的研究现状及发展

我国是水果生产第一大国,水果采收后处理分级有利于销售按级定价,方便贮运;通过检测剔除虫害果和机械损伤果,减轻了病虫害的传播和降低残次品处理成本;对于提高我国果品品质,增强国际市场竞争力有着重要的意义。通过对国内分级检测的技术方法的介绍,分析了目前分级检测技术的不足,提出了相关的发展建议。