Research News

Determination of Maturity Indices of Three Mango Varieties Produced in Embu County of Kenya

Harvest maturity significantly affects the overall quality and shelf life of fruits such as mangoes. Subjective indices often used by producers are unreliable and cannot be used to accurately predict the right maturity for the target market or use. The objective of this study was to determine maturity indices of ‘Tommy Atkins’, ‘Vandyke’ and ‘Kent’ mango varieties produced in a medium-altitude agro-ecological zone, Embu County of Kenya. Mango trees were tagged at 50% flowering and the number of days to the earliest maturity stage established for each variety as stage 1. Subsequent stages (2, 3 and 4) took 7-10 days apart. For each maturity stage and variety, the indices of maturity based on physical, physiological and biochemical parameters were established.

The number of days from 50% flowering to physiological maturity was established as 97, 100 and 114 for ‘Tommy Atkins’, ‘Vandyke’ and ‘Kent’ respectively. Fruits’ flesh firmness decreased gradually with maturity from 40.54 N (stage 1) to 6.84 N (stage 4). Ethylene production and respiratory activity increased with maturity. The ratio of total soluble solids to total titratable acidity increased from a mean value of 25.57 (stage 1) to 109.9 (stage 4). The study revealed that despite the similarity in visual (subjective) parameters, the three varieties differed significantly in other maturity indices. A combination of flesh colour, firmness and computational maturity indices to ascertain harvest maturity for mango fruits can be complemented by the subjective indices used by farmers.

More information is available on The First Africa-wide Postharvest Food Loss Reduction Conference and Exhibition Research Projects

Prof. Ambuko displaying mangoes

Investigating the Yield and Quality Characteristicsof Waste Potato Peel

The economy of developing countries, Kenya included, is still based on agriculture. Potato is one of the crops contributing immensely to Kenya’s agricultural sub-sector. Potatoes are processed into a variety of products such as chips, fries, mashed potatoes and flakes which results in a great amount of peels some of which go to waste. Industrial processing generates between 70 and 140 thousand tons of peels worldwide annually. The wastes from potato processing are mainly potato skins, starch and inert material. Peeling is a major unit operation in the processing of potato.

Besides the amount of waste peeling method also affects the composition of extracted starch content of potato peel waste. Potato peel waste represents a severe disposal problem for the potato industry since wet peels will quickly spoil due to microbial activities.

The failure or inability to salvage and re-use such materials economically results in unnecessary waste and depletion of natural resources. Hence there is a need to encourage the bioconversion of this waste peels into useful products such as starch since they contain a considerable amount of starch. The problem in the extraction of starch from peel waste is that very low yield depending on methods of extraction. The objective of the current study was to determine the yield and quality characteristics of waste potato peel starch as influenced by the extraction method.

More information is available on The First Africa-wide Postharvest Food Loss Reduction Conference and Exhibition Research Projects

Picture of potato seedlings in a farm. Potato is one of the crops contributing immensely to Kenya’s agricultural sub-sector.