Abstract:
In this study, three selected pesticidal plants; Piper guineense, Aframomum melegueta, Capsicum annum were used to determine the shelf life of sun-dried Palaemon hestatus and smoke-dried Parapenaeus longirostris stored for eight weeks. The effects of the plant preservatives were evaluated using untreated sample as the control. There was significant difference (P<0.05) across the colum in the initial and final proximate compositions. The 2 species of shrimps used also revealed significance differences (P<0.05), but ash content showed no significant differences (P>0.05), the values for the smoke-dried species were recorded as 9.19+0.36, 57.02+0.59, 4.50+0.19, 9.50+0.44%, Sun-dried 9.13+0.35, 58.88+0.72, 5.00+0.26, 10.28+0.24%, smoke-dried species shows more stable proximate composition as compared with the sun-dried species. The various treatments differed significantly in their impact during storage and the best result was recorded in samples treated with P. guineense, and C. annum. The various mineral contents of the samples such as Ca, Na, K and P of the treated and untreated samples ranged between 17.91+0.68 to 205.26+1.69mg/100g. The values of Mg content were seen to be extremely lower than other mineral constituent and it ranged between 0.45+0.23 to1.48+0.66mg/100g. Total Volatile Nitrogen (TVN) values of sun-dried and smoke-dried shrimp were still within the tolerable limits of 30mgN/100g after the 8th week of storage which indicates the samples were still good for consumption. These values however varied between the treatments with the lowest value recorded in samples treated with P. guineense as 19.21+0.04mgN/100g, while control recorded the highest value as 29.77+0.14mgN/100g. There was no significant difference (P>0.05) between sun-dried and smoke-dried samples for sensory evaluation, but between the treated and untreated samples there were significant differences (P<0.05). Between the three plant preservative used, P. guineense was found to have the most effective preservative potential on sun-dried and smoked-dried shrimps during storage.
