Fruit quality of South African cactus pear cultivars

[摘要] English: The cultivation of cactus pears requires low input and it has been grown widely in drierareas of South-Africa as fodder crop, particularly for times of serious drought. Cactuspears also serve as a source of inexpensive nutritious food for lower income groupsSugar is the main determent of taste of the cactus pear cultivar and content value rangefrom 10 °Brix to 17 °Brix. Glucose is the predominant sugar with fructose as thesecond sugar, thus the fruit pulp is very sweet. The pulp of the cactus pear cultivarconsists of a high pH value (> 4.5) and low acidity level (0.03-0.12 % ), (SaenzHernandez,1985; Brutch, 1993; Piga, 2004; Salim, 2009).The aim of this study was to determine the fruit quality of cactus pear fruit.Physical/chemical and sensory quality attributes were evaluated for two agriculturalseasons ( 2007 and 2008). The influence of factors such as rainfall and temperatureon quality was determined. Furthermore, sensory analysis was used to distinguishamong the available 33 cultivars, not only for their taste, but also to establish the cultivarmost stable to varying environmental conditions. This study determined whethersensory quality of cactus pear fruit was influenced by the physical/chemical parametersby correlating the physical/chemical data with the sensory analysis.There were highly significant differences observed in terms of physical/chemicalcomposition (p < 0.001) among 33 different cactus pear cultivars in South Africa, forseasons 2007 and 2008. This finding indicated that genetic differences among cultivarsas well as seasonal changes have a significant influence on fruit quality. It was evidentfrom this study that not only the cultivar and agricultural season, but also the interactionbetween the cultivar and season had significant influences on fruit quality.The best preferred cultivar, regarding physical/chemical fruit quality attributes, wasNudosa, performing the best regarding fruit mass and pulp glucose. Messinaperformed the best regarding 0 Bx. Nudosa and Messina performed the best regardingpulp fructose content, while Blue Motto had the best acidity levels (pH and TA).Sensory analysis, used to determine whether the consumer could distinguish among theavailable 33 cultivars was done by using the FCP technique and it was clear that theconsumers could only successfully distinguish between the two seasons (77.72 %) , butnot among the 33 different cactus pear cultivars. The fodder cultivar, Robusta, was anexemption and could be clearly distinguished from the other 32 cultivars.The sensory quality of cactus pear fruit obtained from the consumers was indeedinfluenced by the physical/chemical parameters. Cultivars like Robusta, Fresno andNudosa had been significantly influenced by seasonal differences. Thephysical/chemical data and the sensory attributes were correlated.

[发布机构] University of the Free State