Digestibility of sorghum proteins

Area of Science:

• Nutritional Science
• Food Science

Background:

• Sorghum protein digestibility is significantly lower in children compared to rice, maize, and wheat.
• The weanling rat model fails to accurately reflect these digestibility differences.
• A sensitive laboratory method is needed to assess sorghum protein digestibility.

Purpose of the Study:

• To identify a laboratory system that accurately reflects sorghum protein digestibility differences.
• To investigate the effect of cooking and fermentation on sorghum protein digestibility using pepsin.
• To evaluate the pepsin digestibility of traditional Sudanese sorghum products.

Main Methods:

• Utilized porcine pepsin in vitro to assess protein digestibility.
• Compared digestibility of uncooked and cooked sorghum gruels.
• Analyzed the pepsin digestibility of fermented (kisra, abrey) and unfermented sorghum products.

Main Results:

• Porcine pepsin in vitro accurately demonstrated digestibility differences, unlike the weanling rat model.
• Uncooked sorghum protein digestibility ranged from 78-100%, dropping to 45-55% after cooking.
• Fermented sorghum products (kisra, abrey) showed higher pepsin digestibility (65-86%) than unfermented cooked gruels (44-56%).

Conclusions:

• Porcine pepsin in vitro is a sensitive method for evaluating sorghum protein digestibility.
• Cooking significantly reduces sorghum protein digestibility, while fermentation enhances it.
• Further research on sorghum-based foods in the semiarid tropics is needed to identify more digestible options.