The sericin and purple waxy corn cob extractions were performed, as previously described [13 (link)]. The sericin from silkworm cocoons (J108 strain) was obtained from Queen Sirikit Sericulture Center (Khon Kaen, Thailand) in January 2020. Sericin was extracted by autoclave. The cocoons were aged 42 days at collection. The silkworm cocoon was cut into small square pieces of 1 × 1 cm. Twenty-four grams of the cocoon material was added to 700 mL of purified water and autoclaved (Tomy-SX-700, Tokyo, Japan) at 120 °C, 2.5 bar for 60 min. Then, the mixture was filtered through a Whatman No. 1 filter. The filtrate was then freeze-dried at −85 °C, 0.595 bar (Labconco, Kansas, MO, USA), to obtain the sericin extract.
The purple waxy corn cobs (Thai purple waxy corn) were obtained from the Plant Breeding Research Center for Sustainable Agriculture (Khon Kaen University, Thailand) and extracted by maceration in 50% ethanol (ratio of powder to solvent 1:25), with stirring at 25 °C for 24 h. Then, the filtrate was collected. The residue was then reextracted twice following the same procedure. The filtrates were pooled, evaporated, and then freeze-dried at −85 °C, 0.595 bar (Labconco), to obtain the crude extract (purple waxy corn cob extract, PWCC) [13 (link)]. Both sericin and PWCC were stored and protected from the light at −20 °C.
The purple waxy corn cobs (Thai purple waxy corn) were obtained from the Plant Breeding Research Center for Sustainable Agriculture (Khon Kaen University, Thailand) and extracted by maceration in 50% ethanol (ratio of powder to solvent 1:25), with stirring at 25 °C for 24 h. Then, the filtrate was collected. The residue was then reextracted twice following the same procedure. The filtrates were pooled, evaporated, and then freeze-dried at −85 °C, 0.595 bar (Labconco), to obtain the crude extract (purple waxy corn cob extract, PWCC) [13 (link)]. Both sericin and PWCC were stored and protected from the light at −20 °C.
Free full text: Click here
