Effect of storage period atcold storage on some physical and chemical properties of potato tuber prepared for processing

The aim of this study was to evaluate the effect of storage period and condition on the physical and chemical properties of potato tuber prepared for processing. Two varieties of potatoes namely Diamant and Santana were evaluated for their suitability for industrial production of chips and French fries with respect to storage period. The quality characteristics of the potato samples were examined during cold storage at 10 ⁰C and 75-85% relative humidity and treated with (ChlorphenylIso- Propyl- N-3-Carbamate CIPC) as sprout inhibitor. Physical properties of potatoes were evaluated every 2 months for 6 months throughout 2 seasons. The results obtained showed that there was relative increase on dry matter content ranged between 21.70 % at zero time to 23.73 % at six months for Diamant variety and 21.53 % at zero time to 25.80 % at six months for Santana variety at both seasons. Also there was observed increase in specific gravity from 1.092 at zero time to 1.097 at six months for Diamant variety and 1.086 at zero time to 1.107 at six months for Santana variety at both seasons. For chemical parameters tested there was a decline in starch content 19.51% at zero time to 15.45 % at six months and 19.55 % at zero time  to 16.70 % at six months for Diamant and Santana varieties respectively.. For chemical parameters tested there was a decline in starch content 19.51% at zero time to 15.45 % at six months and 19.55 % at zero time  to 16.70 % at six months for Diamant and Santana varieties respectively. Accordingly there was an increase in reducing sugars from 0.234 % at zero time to 0.278 % at six months and from 0.233 % at zero time to 0.266% at six months for Diamant and Santana varieties, respectively, which affected both quality and consumer acceptability due tonon-enzymatic browning result in darkening of chips and French fries colour. The main recommendations of this study are that the storage condition must be controlled during storage period due to its critical effect on the quality characteristics of potato frying products.