The preservative effects of natural herbs/spices used in meat products.

Sausage production and consumption is gaining prominence daily in Ghana. However, with the erratic power supply, products deterioration in terms of microbial and oxidative spoilage is on the increase. The study was therefore undertaken to curb this sitaution, hence, the objectives of this study were to assess the use of spices/herbs in meat/food preparation in the Kumasi Metropolis and evaluate the possibility of utilizing the essential oils of the spices/herbs as natural antioxidants and antimicrobials. A structured questionnaire was used to assess the utilization of spices and herbs in the study area. Based on the outcome of the questionnaire, spices/herbs of prominence (ginger, onion, chili pepper, prekese and negro pepper) were selected and their phytochemicals and functional properties analyzed using standard method. Essential oils extracted from these herb/spices were included in frankfurter - type sausage. The products were evaluated for physico-chemical properties and keeping qualities (microbial count and oxidative stabilities) using standard procedure. Overall acceptability was determined with 9-point hedonic scale. Data were analyzed using descriptive statistics and ANOVA at p≤0.05. The study showed that more females (75%) consume/use spice/herbs for domestic purposes than their male (25%) counterpart in meat/food preparation. Most of the respondents were Christian youth (26-35 yrs), married with household size less than four and Akan by tribe. Most of them had formal education up to secondary/tertiary level and engaged in business activities. Spices/herbs in powder or whole form were mostly used to make stew, soup, kebabs, sausages and burgers. Similar trend was observed for processors/vendors of meat products who mostly used the spices/herbs to prepare kebabs, sausages and burgers for their customers at an average cost of GH¢11.00 to GH¢15.00 to produce a kg of meat product of which GH¢1.00 - GH¢5.00 was spent on spices. More males were involved in the processing/sale of meat products than males who consumed or used spices/herbs for domestic purposes. Ginger, onion, chili pepper, Negro pepper and prekese were the commonly used spices/herb in culinary activities in the study area. Phytochemicals (phenols, flavonoids, tannins, alkaloids and saponins) were pesent in the spices/herbs. Essential oil (0.05%) from each spice/herb was added in the manufacture of frankfurter sausages and the cooked product stored at -18℃ for three weeks. Proximate composition, free fatty acids (FFA), pH, 1, 1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, microbial load and organoleptic qualities were determined during storage. The study indicated that there were significant (p<0.05) increases in the FFA of all samples during day 7 and day 21 whilst day 14 recorded no significant (p>0.05) increase. In all, the ginger-treated products recorded the least FFA production at the end of storage. Antioxidant activity of prekese, chili pepper and Negro pepper was at its best on the 14th day whilst onion and ginger were stronger at week three. Onion, prekese and ginger gave the best microbial inhibition with Negro pepper and chili pepper inhibiting the least on the third week. Onion essential oil was more effective against Staphylococcus aureus followed by prekese, ginger and chili pepper with Negro pepper being the least effective. Products treated with essential oils of chili pepper, ginger, onion and the control were most acceptable by the taste panelists whilst Negro pepper and prekese essential oil treated products were least accepted on the grounds of taste and aroma. The use of chili pepper, ginger and onion effectively improved eating and keeping qualities of frankfurter - type sausages.

Source: KNUST