ORGANIC PRESERVATION AND SHELF–LIFE EVALUATION OF LIQUID KUNU ZAKI FOOD DRINK, WITH EXTRACT OF WEST AFRICAN BLACK PEPPER (Piper guineense)
Orishagbemi, C. Ojo; Abdulmalik Bushiratu, Isah R. Laisi, Igbatigbi, J. Makoji and Achimugu Solomon
Department of Food, Nutrition & Home Sciences
Kogi State University, Anyigba – Nigeria
Email: cornelosag@gmail.com
Corresponding Author: Orishagbemi, C. Ojo
ABSTRACT:
Organic extract from West African black pepper that contains antimicrobial/antioxidant agents, was prepared and used to preserve liquid kunun zaki along side control sample unpreserved. The extract was applied at four (4) concentration levels (5.0, 10.0, 15.0 and 20.0g extract/L kunun) making four experimental samples and one control properly packaged in plastic bottle (all coded). The samples were stored under ambient conditions, subjected to weekly routine inspection, physical, sensory, microbiological evaluation, shelf-life assessment and data analysis using standard methods in each case. The brix level, specific gravity, pH and titratable acidity of kunun samples were maintained for four weeks in 15.0g extract/Litre sample, found similar to the freshly prepared samples, showing no significant difference (p>0.05). While samples containing 5.0, 10.0 and 20.0g extract/L could maintain these physical properties for less than 3 weeks, before deterioration of sensory properties set in. Samples 10.0, 15.0 and 20.0g extract/L maintained initial high colour and taste ratings for 4 weeks under storage, while unpreserved control and 5.0g extract/L samples experienced rapid decline in colour and taste found to be significantly different (p>0.05). Flavour scores declined in all the samples as storage progressed, while samples 15.0 and 20.0g extract/L experienced the least decrease over 4 weeks duration, not significantly different (p>0.05) from the original high rating, while other samples were found objectionable/rejected at the end of week 3. Sample 15.0g extract/L maintained high mouth – feel rating throughout 4 weeks storage, while the control, 5.0 and 10.0g extract/L samples developed objectionable mouth – feel after week 3 and 20.0g extract/L sample had poor rating throughout storage over 4 weeks. Detected microbiological contents in samples under 4 weeks storage, included total plate count (9.8 x 10I cfu/mL, max), lactic acid bacteria (7.2 x 10I MPN, max), Geotricum spp (6.8×10I MPN/mL), Saccharomyces cerevisiae (8.8×10I MPN, max) and coliform (NIL). The values of each microbiological parameter fall within acceptable/ permissible limits for fermented food beverages, to guarantee safety for consumption. Apparently, 15.0g extract/L sample has the most desirable and acceptable quality attributes under 4 weeks storage at the ambient conditions (i.e. physical, sensory properties and safety), and therefore the extract of West African black pepper is a suitable organic preservative that can replace chemical/synthetic preservation of kunun zaki food drink.
Key words: Organic preservative, Black pepper extract, kunun zaki drink, antimicrobial/antioxidant agents.
