Effects of Mulberry Leaves Extract on the Chemical, Physicochemical and Bioactive Properties on Cheese

Mulberry leaves have been used in traditional Chinese medicines due to its highly valuable phytochemicals contributing to pharmacological activity. However, insufficient study on the extraction of bioactive compounds in mulberry leaves and its effects on cheese and in vitro digestion was presented. The aim of the present study was to investigate the effects of enzyme pretreatment and in vitro digestion on the chemical, physicochemical and bioactive properties of mulberry leaves extract on cheese. Mulberry leaves extract with enzyme pretreatment (pectinase and cellulase) showed better outcomes on TPC, TFC, FRAP and anti-diabetic activity than control mulberry leaves extract while the control mulberry leaves extract (without enzyme pretreatment) obtained higher DPPH (46.22 ± 0.40 %) and anti-inflammatory activity (45.35 ± 0.24 %). Moreover, poor outcomes on the extraction of phenolic and flavonoid compounds and the antioxidant activity (FRAP, DPPH) were observed after fortification of mulberry leaves extract and LAB in cheese. However. cheese with control mulberry leaves extract and cheese with LAB have obtained better anti-diabetic activity (87.16 ± 3.21 %, 89.76 ± 1.81 %) and anti-inflammatory activity (21.69 ± 2.33 %, 28.43 ± 0.54 %) compared to the others. The effects of in vitro digestion on the cheese with mulberry leaves extract and LAB were also presented in this study. After gastrointestinal digestion, poor outcomes were observed on the TPC, TFC and FRAP of cheeses while positive outcomes were obtained on the DPPH, anti-diabetic and anti-inflammatory activity in the cheeses. The DPPH activity of 88.97 ± 0.59 % of cheese after intestinal digestion and anti-diabetic activity of 90.74 ± 3.09 % after gastric digestion was the highest among all the cheeses. These studies provided the scientific data for the effects of enzymatic treatment, fortification in cheese and in vitro digestion on the bioactive properties of mulberry leaves extract.