ผลของลิพิดและการบ่มด้วยความร้อนต่อสมบัติของฟิล์มอิมัลชันโปรตีนถั่วเหลือง

• 主要作者: นลินทิพย์ คงแก้ว
• 其他作者: ธนจันทร์ มหาวนิช
• 格式: Theses and Dissertations
• 語言: Thai
• 出版: จุฬาลงกรณ์มหาวิทยาลัย 2011
• 主題: โปรตีนถั่วเหลือง; Soy proteins
• 在線閱讀: https://digiverse.chula.ac.th/Info/item/dc:34697
• 機構: Chulalongkorn University

The objective of this study was to investigate the effect of lipid incorporation and heat curing on properties of soy protein isolate film. In the first part of the study, the effect of type and concentration of lipid on film properties was examined. The lipids used in this study were palm kernel oil, hydrogenated palm kernel oil, palm oil, hydrogenated palm oil, soybean oil and hydrogenated soybean oil. Lipid concentration was varied at 10 and 20% by weight of soy protein isolate. The emulsion films were found to exhibit higher thickness and lower transparency, as compared to the film with no added lipid (control) (p≤0.05). In terms of mechanical property, lipid incorporation resulted in an emulsion film with lower tensile strength than the control while elongation at break was affected only slightly by lipid addition. Adding lipid was shown to help improve the film hydrophobicity, as shown through a decrease in water vapor permeability and water solubility and an increase in contact angle with a water droplet (p≤0.05). Lipid concentration, on the other hand, did not place an important effect on properties of the emulsion film. The films added with 10 and 20% lipid possessed similar properties. Hydrogenation of lipid, in contrast, significantly affected the emulsion film properties. The films containing hydrogenated lipid demonstrated lower tensile strength and elongation at break, and higher hydrophobicity than those containing non-hydrogenated lipid. From this study, greatest hydrophobicity was denoted by the film containing 20% hydrogenated palm kernel oil. However, this film sample was inferior concerning the mechanical property. In the second part, the study of the effect of heat curing of film-forming solution was carried out. The film containing 20% hydrogenated palm kernel oil was used. The curing was done at 70, 80 and 85 °C for 30, 45 and 60 min. Curing of film-forming solution at 70 °C for 60 min resulted in a film with greatest tensile strength and elongation at break. However, heat curing of film-forming solution caused a decrease in the film hydrophobicity, as evidenced by the increased water vapor permeability and water solubility, and the decreased contact angle. In the third part, the effect of heat curing of the dried film was investigated. The film samples used were those obtained by curing the film forming solution at 70 °C for 60 min and at 85 °C for 45 min. The dried film samples were heated at 70, 80 and 90 °C for 0, 5 and 10 hrs. Heat curing of dried film was shown to help increase tensile strength while the film elongation at break was found to decrease. Moreover, heat curing of dried film helped improve the film hydrophobicity. The dried films cured at 90 °C for 10 hrs possessed the greatest tensile strength and contact angle while being lowest in water vapor permeability and water solubility.