White mulberry leaf (Morus alba L.) infusion as a strategy to reduce starch digestibility: The influence of particle size of leaf powder
Thiraphong Aumasa,
Gunthawan Apinanthanuwong,
Jaspreet Singh,
Lovedeep Kaur,
Jinhu Tian,
Suphat Phongthai,
Yardfon Tanongkankit,
Utthapon Issara,
Yukiharu Ogawa,
Natthawuddhi Donlao
Affiliations
Thiraphong Aumasa
Unit of Innovative Food Packaging and Biomaterials, School of Agro-Industry, Mae Fah Luang University, Chiang Rai 57100, Thailand; Graduate School of Horticulture, Chiba University, 648, Matsudo, Matsudo 271-8510, Japan
Gunthawan Apinanthanuwong
Unit of Innovative Food Packaging and Biomaterials, School of Agro-Industry, Mae Fah Luang University, Chiang Rai 57100, Thailand; Graduate School of Horticulture, Chiba University, 648, Matsudo, Matsudo 271-8510, Japan
Jaspreet Singh
School of Food Technology and Natural Sciences, Massey University, Palmerston North 4442, New Zealand; Riddet Institute, Massey University, Palmerston North 4442, New Zealand
Lovedeep Kaur
School of Food Technology and Natural Sciences, Massey University, Palmerston North 4442, New Zealand; Riddet Institute, Massey University, Palmerston North 4442, New Zealand
Jinhu Tian
College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Fuli Institute of Food Science, Zhejiang University, Hangzhou, China
Suphat Phongthai
Division of Food Science and Technology, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai 50100, Thailand
Yardfon Tanongkankit
Department of Agricultural and Food Engineering, Faculty of Engineering and Agro-Industry, Maejo University, Chiang Mai 50290, Thailand
Utthapon Issara
Division of Food Science and Technology Management, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Pathum Thani 12110, Thailand
Yukiharu Ogawa
Graduate School of Horticulture, Chiba University, 648, Matsudo, Matsudo 271-8510, Japan; Corresponding author.
Natthawuddhi Donlao
Unit of Innovative Food Packaging and Biomaterials, School of Agro-Industry, Mae Fah Luang University, Chiang Rai 57100, Thailand; Tea and Coffee Institute, Mae Fah Luang University, Chiang Rai 57100, Thailand; Corresponding author at: Unit of Innovative Food Packaging and Biomaterials, School of Agro-Industry, Mae Fah Luang University, Chiang Rai 57100, Thailand.
Mulberry leaf (Morus Alba L.) has been found in clinical trials to be effective in reducing diabetes in Asia. The powdered tea market is expanding in popularity due to its functional properties. This study aimed to examine the influence of different particle sizes of mulberry leaf powder (MLP) infusion on the digestibility of starch in cooked Japonica rice (cv. Koshihikari) and the bioaccessibility of phytochemicals. Dried mulberry leaf was pulverized and sieved into several particle sizes: 160 μm (MLP160), 250 μm (MLP250), 404 μm (MLP404), and 774 μm (MLP774). Through simulated in vitro digestion, we assessed starch hydrolysis (%SH), the kinetics of starch hydrolysis, estimated glycemic index (eGI), as well as total phenolic content (TPC) and total flavonoid content (TFC). The smaller particle size of MLP showed a greater reduction of eGI. Specifically, infusions prepared from MLP160 resulted in a reduction of 15 % in eGI for cooked grains and 3 % for slurries, respectively. The reduction in eGI was attributed to the interaction among flavonoids and digestive enzymes, demonstrating a concentration-dependent manner on enzyme inhibition effect. Pulverization significantly influenced the concentration of phytochemicals and their bioaccessibility in infusions. This study offers valuable insights into determining optimal particle sizes for MLP, considering both physical and functional characteristics as well as implications for the food industry. The results further suggest that MLP infusion holds promise as a functional beverage, potentially providing benefits in reducing postprandial hyperglycemia.
