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Part
3, Chapter 7
Case studies: product development in the food system 7.2.2 Study implementation Selection of varieties
sucrose content and the increase in fructose and glucose. Succinic acid was the most prominent acid, while malic and citric acids were also important; individual contents of these acids varied and could be used as indicators of varieties. Aroma volatiles were measured by gas chromatography. Detailed contents were explored, and the total volatile contents were found to vary with varieties.
To start the study, a group gathered information on the varieties of mangoes that were produced in Thailand and also overseas. These were then carefully con- sidered with respect to usage, production technologies, transportation and storage durability, and eating characteristics. The available literature was inspected, and mango growers and the trade were canvassed to gain requisite information so that the group could select the most promising varieties, those most likely to form the basis of a viable and growing industry, for further investigation in detail. Physical properties of the fruit One group looked at physical properties which were fruit weight, fruit size, seed size, seed weight and thickness, skin and flesh weight and thickness, skin and flesh colour, and flesh texture. Chemical analysis Another group looked at chemical contents and measured moisture, total soluble solids, acidity, sugar, beta-carotene (vitamin A). Also the sugar/acid ratios were noted. Chemistry of flavours Flavour constituents were measured including sugars, acids and aroma volatiles. For example, they showed the extent, as the fruit ripened, of the decline in the Consumer preferences Consumer preferences to determine the degree of liking on a nine-point hedonic (liking) scale, were carried out in a central location test, on varieties of Thai mangoes using Chinese, Hong Kong, Japanese, Middle East and Thai consumers, settled in Thailand. The objective was to select the best Thai mango for export, based on the sensory characteristics most preferred by the target consumers. The sensory characteristics used, for the fruit and the flesh of the mangoes, were skin colour, fruit size, flesh texture and overall liking for the flesh. Overall the results showed that the fruit shape, fruit aroma and skin appearance were more highly correlated with overall liking than the other attributes. A single variety emerged as the preferred one overall, though to some extent rankings of mangoes varied with the attributes. National preferences The degree of liking and disliking for sensory characteristics of the ripe fruit and the flesh of two varieties of the mangoes were explored with about 600 Chinese and 400 Japanese tourists in Thailand. Attributes such as skin appearance, fruit colour, fruit size and shape, flesh colour and flavour, and fruit aroma were covered, as well as overall liking; using hedonic scales. From this emerged attribute profiles for the varieties, and one variety preferred by both groups. Systematic attribute relationship analysis A systematic comparative technique known as quantitative descriptive analysis (QDA) was employed by another group to look at six of the mango varieties and to build associations between the sensory attributes of the varieties. The results indicated that the difference among fully ripe mangoes was most pronounced on the perception of fruit size, weight, thickness and fruit aroma strength. This showed, for example, that the variety that was emerging as the preferred one was the smoothest, juiciest and most tender, but not the biggest, heaviest or thickest, nor did it have the heaviest fruit odour. Conclusions about the fruit Overall from these experimental results a variety emerged which on balance was preferred by the majority of consumers from each of the countries sampled. The preferred variety, both fruit and flesh, was the Num Dok Mai See Thong mango, followed by Rad and Ma Ha Cha Nok. Additionally, and importantly, this choice was for reasons that could be differentiated and substantiated. The sensory results were supported by extensive information on the fruit, the flesh and the association of desired mango attributes. The study results therefore provided clear signals statistically based on consumer responses. The signals were to the growers for plant selection and cultivation, to the trade for technical details in handling, storage and exporting, and to the plant breeders for selection of characteristics on which to concentrate and for further experimentation. |
 7.2.3
Commercial aspects Back
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