PHL management of guava fruit by using locally developed solar pasteurizer technology

This paper deals with PHL management of Guava fruit through small-scale juice processing in rural areas that have no access of modern energy. Guava trees cover large areas in Tigray region of Ethiopia, however, during the harvest period the consumption and yield of the fruit is not in balance. Consequently, considerable amount of the fruit spoiled in the field. In addition, during this period the market price of the fruit is very low and discourage farmers to collect the fruit as its market price could not cover the labor cost. On the other hand, the fruit is not available out of the yield season. This study has demonstrated fruit processing using locally developed solar energy technologies to improve PHL management of fruits and vegetables. The technology has sized in view of smallholding farmer’s production capacity with an average power of 6kW at an average solar insulation of 800 W/m2 that boils 5 l of water in 5 min. During the experiment, uniformly sliced fruits were boiled using the solar boiler for half an hour to make it sterilized and soft. The boiled fruit was mixed with preservatives, homogenized, filtered and hot-filled into a glass bottle to avoid air traps. The juice examined regularly in 30, 60 and 90 days for its PH, TSS and total microbial load. The results have shown the average total bacteria counts of the juices is below the maximum allowable limit in foods for consumption. Accordingly, the technology would enable smallholding farmers to start equitable agroprocessing.