The nutritional and economic potential of tofu dreg (okara) and its utilization for high protein food products in Indonesia

About one million tons of tofu dreg or okara, a solid waste from tofu processing, is generated annually by 84,000 tofu industries in Indonesia. Tofu dreg contains considerable nutrients and bioactive components, suggesting its potential utilization for food and feed. Being high in protein, traditional fermented foods, such as tempe gembus and oncom, have long been known as tofu dreg products in some regions. Many developed food products with considerable protein from fresh tofu dreg, and its flour have also been studied to support local food diversification. Additionally, the economic value of tofu dreg is essential as it contributes significantly (10-65%) to the tofu processor's income through selling this waste alone, particularly for goat or cow fodder. More added values can be obtained by processing tofu dreg into various food products ranging from 0.40 up to 582 times. It suggests that a more significant amount of tofu dreg used for food purposes is essential in the future by developing good quality, attractive, nutritious, safe, and affordable products in the market, followed by intensive promotion to the consumers. Selected products originating from other countries are likely promising to be developed as well. Therefore, tofu dreg, previously assumed to be a waste in the tofu industries, must be appropriately handled as a food material. Overall, this review covers the current and promising utilization of tofu dreg for food in Indonesia and its economic added value.