Tempe is vital for the adequate nutrition of many Javanese, whose diet is rice based and contains little animal food. Rice is high in protein, but these proteins are low in the essential amino acid lysine. Soya beans have plenty of lysine, but even after the beans are cooked much of this protein is physically and chemically locked up and cannot be digested. The mould used in tempe fermentation produces enzymes which break up and ‘pre-digest’ the protein and make it accessible to human digestion. Indeed, as Sri Owen (1986) remarks:
Nutritionists and cooks must agree that tempe has a lot going for it. It contains about 40 per cent protein—more than any plant or animal food—carbohydrates without starch, unsaturated oil without cholesterol, all eight essential amino acids, Vitamin A and several B-complex vitamins, iron, calcium, zinc, phosphorus and magnesium. It can be frozen at almost any stage in its manufacture or preparation.