Abstract:
Effect of phytochemical constituents of commonly found herbs and spices on shelf life of
ground chicken meat was studied. Five different herbs and spices viz. onion leaves, garlic
leaves, hattibar leaves, radish leaves and chiraito were collected and their methanolic
extracts prepared. The extracts were then analyzed for total phenols, total flavonoids, total
tannin and total radical scavenging capacity. The extract of each sample was incorporated in
the ground meat at the concentration of 100 ppm, 200 ppm, 300 ppm, 400 ppm and 500 ppm
of total ground meat mass. Then the subsequent changes in thiobarbituric acid reactive
substances (TBARS) value and total plate count (TPC) of the ground meat was studied at 0,
4, 7, 10 and 12 days in the refrigerated system at 4°C.
The highest amounts of phenols, flavonoids, tannins and antioxidant activity were found
in the methanolic extract of onion leaves (99.34±2.92 mg GAE/g), radish leaves (53.04±0.41
mg QE/g), onion leaves (26.58±0.16 mg tannic acid/g) and chiraito (IC50= 24.96±0.40
µg/ml) respectively. Similarly, the lowest amounts of phenols, flavonoids, tannins and
antioxidant activity were found for methanolic extract of hattibar leaves (13.27±0.69 mg
GAE/g), garlic leaves (16.62±2.97 mg QE/g), radish leaves (10.72±0.059 mg tannic acid/g)
and hattibar leaves extract (IC50=952.28± 1.43 µg/ml) respectively. The untreated meat
sample exceeded the threshold TBARS (1 mg MDA/kg) value on 7
th days of storage and
only 100 ppm of garlic leaves extract, chiraito extract and radish leaves extract incorporated
samples exceeded threshold value on 12th days of storage. Highest and lowest TBARS values
were obtained from untreated meat sample (1.71±0.82 mg MDA/kg sample) and 500 ppm
of chiraito extract incorporated meat (0.24±0.01 mg MDA/kg sample) on 12th days of
observation. In term of antimicrobial activity, only the control and 100 ppm of onion leaves
incorporated samples exceeded legal threshold value (107
cfu/g) on 4
th days and remaining
samples exceeded on 10th days of storage except 500 ppm chiraito extract incorporated which
exceeded on 12th days. And effectiveness increased with increased in concentration of each
extract. Thus, garlic leaves extract, onion leaves extract, radish leave extract, chiraito extract
and hattibar leaves extract significantly increased the shelf life of meat as compare to
untreated meat sample
Description:
A dissertation submitted to the Department of Food Technology, Central Campus of
Technology, Tribhuvan University, in partial fulfillment of the requirements for the
degree of B. Tech. in Food Technology
