Quantification and Storage Studies with Total Phenols Content and Percentage Antioxidant Activities of Piper Guineense Leaves

Abstract

The concern of this work in part, was to investigate the total
phenols levels and antioxidant activity of Piper quineense leaves.
Another portion of this study entailed the determinations of the
responses of total phenols levels and antioxidant activity of Piper
quineense leaves to sun drying, grating and storage using different
facilities. Piper quineense leaves samples used in this study were
obtained from some markets in Benin City, Edo State. Samples were
stored under ambient conditions in the open laboratory and at
water activities (aw) of 0.23, 0.52 and 0.97. Storage duration was
two months. All determinations carried out in this study were done
in accordance with standard methods. Findings indicated that in
raw Piper guineense leaves, total phenols level was 0.69±0.14mg.
Total phenols content of sun dried and grated Piper guineense
leaves was 0.71±0.22mg/g. With respect to the storage studies, at
the end of the storage time, values obtained for total phenols in sun
dried, grated stored Piper guineense leaves ranged from
2.87±0.83mg/g to 6.11±0.73mg/g for samples stored in the open
laboratory, then between 5.63±1.02mg/g and 10.49±1.15mg/g for
samples stored at different aw. It is further discernible from findings
that the percentage antioxidant activity of Piper guineense leaves
studied was 86.21±2.13%. Equally deducible from results was that
sun drying and grating of Piper guineense leaves, then storage of
sun dried and grated Piper guineense leaves led to reduced
retention of antioxidant activity of Piper guineense leaves. Storage
changes noted for total phenols level and percentage antioxidant
were statistically significant (P<0.05) with respect to the storage
conditions studied. It is important that the factors observed in this
study which affects the parameter examined, be taken into
consideration in the handling of Piper guineense leaves.