Diet-related diseases such as obesity, diabetes, cardiovascular disease, hypertension, stroke, and cancer are escalating in developed and developing countries due to imbalanced food consumption patterns and have become a major burden for the public health sector.
Health experts are convinced of the multiple benefits of consuming vegetables and fruits and the urgency to take preventive action to control diet-related diseases. The World Health Organization recommends that consumers eat at least 400 grams of fruit and vegetables a day, while the World Cancer Research Fund would like to see this threshold level raised to 600 grams per day.
As fruit and vegetables, especially traditional vegetables, are rich sources of vitamins, micronutrients, and antioxidants, encouraging frequent consumption of these crops is a good strategy to combat micronutrient deficiency. But are modern vegetable varieties really nutrient-dense?
Recent studies have shown that breeding for high yield, visual appearance, and long shelf life may lead to an unintentional decline in taste and the content of some essential nutrients. This was the case for wheat grain, potato tubers, and a number of horticultural crops.
Studies undertaken by AVRDC have shown that traditional vegetables have a much higher density of essential phytonutrients than global vegetables like tomato and cabbage. There are also reports in the literature that the early growth stages of vegetable crops have higher nutrient density than fully grown vegetables.
Mungbean sprouts are very good sources of ascorbic acid, reaching levels above 50 mg ascorbic acid/100 g fresh weight. Due to increased activities of hydrolytic enzymes during sprouting, there is a loss in total dry matter, starch, and antinutrients such as phytic acid and polyphenols and an increase in essential amino acids, sucrose and reducing sugars, and vitamins. Sprout digestibility is improved due to the partial hydrolysis of storage proteins and starch during sprouting.
Through a new project funded by the Council of Agriculture of Taiwan, AVRDC is studying the levels of essential micronutrients and consumer preferences of selected legume crops (mungbean, soybean) and traditional vegetables (amaranth, mustard, radish) at different growth and consumption stages: (a) sprouts, (b) microgreens (seedlings harvested when the first true leaves appear) and (c) fully grown plants. The comparison includes landraces from AVRDC’s genebank and modern cultivars available commercially.
Should this research prove that local vegetable varieties have higher nutrient levels than modern cultivars of the same crop species and that sprouts and microgreens are characterized by a higher phytonutrient content than fully grown vegetables, this specialty produce would then be an ideal vehicle to deliver exceptional flavor and taste, and high phytonutrient content to consumers with micronutrient deficiencies.
As sprouts and microgreens are usually consumed raw, there is no loss or degradation of heat-sensitive micronutrients through food processing. An additional advantage of sprouts and microgreens is the fact that they can easily be grown in urban or peri-urban settings where land is always a limiting factor.