The Nutritive Quality and Antioxidant Activity of Some Vegetable Soups During Frozen Storage

Abstract

Background: Storage of soups at -18 ℃ are used to preserve and avoid nutritional losses which may arise as a result of periodical heating. Unfortunately, continuous supply of electricity is not always available to majority of Nigerian homes resulting to an adverse loss of soup quality due to several thaw cycles.
Objective: To evaluate the nutritive composition and antioxidant activity of some vegetable soups during frozen storage.
Materials and Methods: Ugu (TVS) and oha (PVS) vegetable soups were prepared with some other ingredients. Standard methods were used to evaluate the nutritive composition and antioxidant activity of the soups during frozen storage.
Results: The results showed that the proximate values of TVS soup: fat (15.15 – 15.80%), fibre (13.00 – 13.80%), protein (17.15 – 18.30%), and ash contents (10.70 – 10.90%) were significantly (p<0.05) higher than the fat (10.70- 11.60%), fibre (9.00 – 9.80%), protein (15.35 – 16.0%), and ash contents (8.90 – 9.60%) of PVS soup. Minerals (Mg, P, Zn, Fe) and vitamins (A and E) followed the same trend. However, there was stronger scavenging power of %DPPH, ABTS and FRAP in PVS than TVS soup. %DPPH, ABTS and FRAP values were 60.86 – 62.04%, 26.42 – 27.52 mg/GAE/g, and 20.02 – 20.63 μmolTE/g in PVS soup, whereas, that of TVS soup were 37.68 – 43.12%, 3.04 – 3.75 μmolTE/g, and 8.26 – 10.43 mgGAE/g. It was observed that polyphenols and vitamin C contributed to strong DPPH, ABTS, and FRAP scavenging activity.
Conclusion: The soups can serve as functional food, improve nutrition and the boosting of physiological health to consumers.