Effect of sunlight exposure on the nutrient composition of two selected commercial milk drinks

  • U.I. Nnubia Department of Home Science and Management, Faculty of Agriculture, University of Nigeria, Nsukka, Enugu State, Nigeria
  • C.L. Ezeonyeche Department of Home Science and Management, Faculty of Agriculture, University of Nigeria, Nsukka, Enugu State, Nigeria
  • E.J. Nnodim Department of Home Science and Management, Faculty of Agriculture, University of Nigeria, Nsukka, Enugu State, Nigeria
  • F.O. Okechukwu Department of Home Science and Management, Faculty of Agriculture, University of Nigeria, Nsukka, Enugu State, Nigeria
  • B.C. Joseph Department of Home Science and Management, Faculty of Agriculture, University of Nigeria, Nsukka, Enugu State, Nigeria
Keywords: Sunlight exposure, Commercial, Milk drinks, Proximate, Vitamins, Minerals

Abstract

Background: Healthy eating involves getting the most out of the nutrients in a particular food. Commercial milk drinks have been found to be good sources of important nutrients; however, the practice of displaying goods under sunlight by retailers, lead to loss of some of these nutrients.

Objectives: This study determined the effect of sunlight exposure on proximate, vitamin and mineral contents of two selected commercial milk drinks.

Methods: The study design was experimental and standard methods were used for nutrient analysis. Six samples each, of the brands were procured from Ogige Market, Nsukka, Enugu State and were randomly divided into treatment and control groups. Two treatment groups were exposed to sunlight, 8 hours daily for 5 days and 10 days respectively under the average weather temperature of 23.4oC and 23.2oC respectively. Two control groups were kept indoors at 21oC average room temperature. Analysis for both treatment and control groups were carried out on days 0, 5 and 10 in duplicates, and mean values determined. Analysis of variance was used to compare mean values of the three tests while independent sample t test was used to compare means of the treatment and control groups

Result: In sample A, protein decreased by 38.9%, from 1.31% to 0.8% at day 10. Calories increased from 72.97% to 95.32% at day 10. Vitamin B9 decreased by 100% by day 5 and Calcium decreased from 11.47mg/100ml to 2.56 mg/100ml at day 5 showing77.6% decrease. In sample B, fat decreased by 26.4%; Vitamin C decreased by 31.2% and phosphorus decreased by 40.6%. The two control groups also lost some nutrients during storage but significantly (p <0.05) less than the treatment groups.

Conclusion: Thus, the study concludes that exposure of milk products to sunlight, leads to more nutrient depreciation compared to storage at room temperature. 

Published
2020-06-30
Section
Articles

Journal Identifiers


eISSN: 2635-3326
print ISSN: 2141-8209