Yellow variety of sweet potato tubers lots were processed with different pre-drying treatments of peeled washed chips: Unblanched without Sodium Metabisulphite (UB-SMBS), blanched without sodium metabisulphite (B-SMBS), unblanched with sodium metabisulphite (UB+SMBS) and blanched with sodium metabisulphite (B+SMBS) for production of dried chips for confectionery flours. Low moisture contents in the range of 2.48 to 5.00% were achieved for the dried chips lots in 20 h of drying at about 55 to 60°C using NSPRI's Cabinet Crop Dryer without smoking. The dried chips had no visible mould growths in the duration of drying and mould loads were low (in the order of 10 2 cfu/g). However, different colours and textures were observed in dried chips and flours depending on pre-drying treatment. While UB-SMBS and UB+SMBS sweet potato chips' flours were suitable and acceptable for production of chin-chin, the B-SMBS and B+SMBS were unsuitable and unacceptable at 100% composition of the flour.

Kinetic data obtained from acid demineralization (using 1.25 N hydrochloric acid solution) of deproteinized exoskeleton of shrimp was fitted to the shrinking core models for heterogeneous reactions. The element of interest was calcium which was the most abundant element in the deproteinized shrimp (66.27%) and the mostly affected by the demineralization. Experimental kinetic data was fitted to the shrinking core model for fluid-particle reactions. Chemical reaction controlled mechanism gave the best predictive model, as depicted by the fit (R 2 = 0.92), with a time of complete reaction of 3 h.