Optimization of pasteurized milk with soymilk powder and mulberry leaf tea based on melatonin, bioactive compounds and antioxidant activity using response surface methodology

Jintana Sangsopha; Anuchita Moongngarm; Nutjaree Pratheepawanit Johns; Nigel Peter Grigg

doi:10.1016/j.heliyon.2019.e02939

Optimization of pasteurized milk with soymilk powder and mulberry leaf tea based on melatonin, bioactive compounds and antioxidant activity using response surface methodology

Heliyon. 2019 Nov 29;5(11):e02939. doi: 10.1016/j.heliyon.2019.e02939. eCollection 2019 Nov.

Authors

Jintana Sangsopha¹, Anuchita Moongngarm¹, Nutjaree Pratheepawanit Johns², Nigel Peter Grigg³

Affiliations

¹ Research Unit of Nutrition for Health, Department of Food Technology and Nutrition, Faculty of Technology, Mahasarakham University, Kuntarawichai Maha Sarakham, 44150, Thailand.
² Faculty of Pharmaceutical Sciences and Melatonin Research Group, Khon Kaen University, 123 Mittaparp Highway, Khon Kaen, 40002, Thailand.
³ School of Food and Advanced Technology, Massey University, Private Bag 11 222, Palmerston North, 4442, New Zealand.

Abstract

Melatonin is a natural hormone which regulates human circadian rhythms and is presented in milk at low concentrations. To improve melatonin concentration and amounts of bioactive compounds in pasteurized milk (PM), soymilk powder (SMP) and mulberry leaf tea (MLT) were added using mixture design response surface methodology (RSM) and levels of SMP, MLT and raw milk (RM) were optimized. PM containing 4.50% SMP, 4.50% MLT and 88.80% RM gave the highest chemical compositions, bioactive compounds and antioxidant activity. Mathematical models of chemical compositions, bioactive compounds and antioxidant activity showed significant differences, whereas sensory attributes were not significantly different in all modeled parameters. Optimum levels were 3.90% SMP, 4.50% MLT and 89.40% RM. Verification of optimum proportions showed that experimental values of chemical compositions, bioactive compounds and antioxidant activity agreed with model predictions. Optimum PM contained melatonin (1.49 ng/mL), free tryptophan (0.26 μg/mL), and total phenolic content (0.72 mg GAE/mL) with high antioxidant activity when assayed by DPPH, ABTS and FRAP. Results suggested that mixture design RSM has the potential to optimize SMP, MLT and RM levels to obtain PM with increased amounts of bioactive compounds and high melatonin content.

Keywords: Consumer sensory research; Food analysis; Food chemistry; Food composition; Food processing; Food technology; Melatonin; Mixture design; Nutrition; Pasteurized milk; Response surface methodology; Sensory evaluation.