DEVELOPMENT AND PERFORMANCE EVALUATION OF A MELON WASHING MACHINE FOR SHORT PERIOD FERMENTED MELON MATERIALS

Abstract

A melon seed washing machine was designed and fabricated for washing short period fermented melon materials obtained from depodded fresh melon pods. The developed melon seed washing machine has four components; the washing basket, impeller disk, impeller shaft and electric motor. The developed melon seed washing machine was evaluated at fermentation and washing stages. During evaluation three operational factors were varied, screen size (S) at four levels (15, 20, 25 and 30 mm), fermentation period (F) at three levels (2, 4 and 6 days) and bag type (B) at three levels (jute, black and white polyethylene bags). The statistical design was 4x3x3x3 factorial experimental design replicated thrice and 108 experimental runs were made during evaluation of melon washing machine. Statistical software SPSS 18 was used to carry out statistical analysis of variance (ANOVA) and Duncan’s New Multiple Range Test (DNMRT) on the evaluation data of the melon washing machine. The statistical results of the (ANOVA) and (DNMRT) of the melon washing machine showed that only the fermentation period and its interactions with bag type has significant effect on the washing performance index (WPI) of the machine at 95 % confidence level. Also, the evaluation experimental data of the machine were subjected to further statistical analysis using SPSS to plot graphs that showed the interactions between the operational factors and the parameters. The graphs revealed that washing performance index (WPI) increases from 77 % to 98 % as fermentation period progresses from 2, 4 and 6 days. The melon seed washing capacity (C_S) of the melon washing machine was measured to be 51.84 kg/h. Again, evaluation results showed that melon samples in black and white polyethylene bags fermented faster (i.e. 2^nd and 4^th days) and easier to wash with the washing machine than the samples in jute bags which fermented lately (i.e. 6^th days) and full of undigested melon chaff when dried. In addition, melon seeds that were fermented in jute bags appeared darker in colour after washing. Therefore, using polyethylene bags for fermentation produces better results than jute bags. Hence, the new melon processing technique for extracting and washing melon seeds from its pods is a fast and efficient technique.