QUALITY ATTRIBUTES OF BROILER CHICKEN MEAT AND PATTIES AS INFLUENCED BY WALNUT (Plukenetia conophora MULL.ARG.) AND MELON (Citrullus colocynthis (L) SCHRAD.) SEED MEAL

Abstract

Chicken meat and its products are prone to Lipid Peroxidation (LP) during storage. Synthetic Antioxidants-SA which could be harmful to consumers are often added to broiler chicken diets or to meat to mitigate LP. Natural antioxidants from plant sources such as Walnut Seed-WS and Melon seed- MS could replace SA. Information on the use of WS and MS as sources of antioxidant for broiler chicken meat and patties is scanty. Therefore, WS and MS as antioxidant sources in broiler chicken meat and patties were investigated. Precisely, 1kg each of WS and MS was boiled for one hour and oven-dried for 12 hours to obtain Treated WS-(TWS) and Treated MS -(TMS), respectively. Milled samples of Raw -WS and MS, TWS and TMS were assayed for flavonoids (mg/100g) and Total Tocopherol-TT (mg/kg) using standard procedures. Arbor Acres Plus chicken (n=336, r=6) aged 21 days, weighing 452±0.21g were randomly allotted to a basal diet supplemented with TWS (g/kg) at 0.0 (T1), 2.0 (T2), 4.0 (T3), 6.0 (T4), TMS (g/kg) at 2.0 (T5), 4.0 (T6) and 6.0 (T7) in a completely randomised design with eight birds/replicate. At day 42, four chickens were randomly selected from each replicate, slaughtered and meat samples assayed for LP (mg MDA/100g), and lightness (colour) parameter determined using standard procedures. Breast meat samples from T1 were processed into patties with TWS included at 0.0 (S1), 2.0 (S2), 4.0 (S3) and 6.0 (S4) and TMS at 2.0 (S5), 4.0 (S6) and 6.0% (S7). Patties were cooked for 7 minutes (72oC) and stored (-18oC). Patties Overall Acceptability (OA) was assessed by panellists (n=20) immediately after cooking, LP and lightness were assessed at seven-day intervals for 28 days using standard methods. Data were analysed using descriptive statistics, regression and ANOVA at α0.05. Flavonoids of MS (20.59±0.01), TWS (21.13±0.02) and TMS (21.15±0.02) were significantly higher than WS 12.51±0.01. Also, TT of raw WS (69.40±0.10) and TWS (58.65±0.24) were significantly higher than those of raw MS (3.07±0.01) and TMS (3.06±0.02) showing that cooking increased the flavonoids but reduced TT compositions. The LP of 0.006±0.002 and 0.006±0.001 were least in T3 and T4, respectively and highest in T5 (0.008±0.02). The OA values of T1 (6.85±0.04), T4 (6.75±0.03), T5 (6.75±0.05), T7 (6.70±0.03), T6 (6.60±0.05) and T2 (6.60±0.06), were similar but significantly lower than T3 (7.50±0.02). Also, the OA of S3 (7.55±0.02) was significantly higher than in other treatments, while S7 (5.90±0.04) had the least. The LP was significantly higher in T6 (0.10±0.01), T4 (0.11±0.12) and T7 (0.15±0.01) than T3 (0.05±0.02). The LP of S3 (0.11±0.01), S5 (0.11±0.02), S6 (0.11±0.04) and S7 (0.11±0.03) were similar but higher than S4 (0.04±0.02). Lightness was higher in T1 (59.39±0.10) than T7 (54.67±0.09). The lightness of 59.39±0.10 in S1 was significantly higher than 46.00±0.11 in S4. Lightness of patties (T1-T7 and S1-S7) decreased linearly (R2=0.99) with days of storage. Cooking enhanced the flavonoid concentration of walnut seed meal. Patties developed from chickens fed walnut and melon seed meal were of lower quality but more acceptable.