This disclosure is concerned with a nutritional product, nutritional composition, and methods for manufacturing thereof. The nutritional product and composition are protein rich substances which include oilcake produced by a process involving steam explosion of raw oilcake such that dry matter left after oil extraction from sunflower seeds or other oily crops or nuts. According to one aspect of this disclosure, there is provided a nutritional product which is suitable for human consumption and comprises a high-protein main ingredient and a supplemental ingredient. The high-protein main ingredient includes sterile and palatable matter such as processed oilcake produced by steam explosion of substantially water-insoluble matter. The optional supplemental ingredient includes one or more of the following: carbohydrates, proteins, and fats.