Choosing Legumes Wisely in August
There are over 11 types of legume vegetables available in the market, with protein content typically ranging from 35% to 40%, earning them the nickname “plant meat.” They are also rich in vitamins and minerals, especially calcium, phosphorus, and iron. Legumes contain no cholesterol, and their fats are mostly unsaturated fatty acids—ideal for people with hypertension, coronary heart disease, high cholesterol, and arteriosclerosis. Common legume vegetables include: green soybeans, yardlong beans, cowpeas, flat beans, snap peas.
Green soybeans currently available are mostly mid- to late-season varieties. Late-season soybeans have larger, softer beans with a chewy texture, making them tastier than those sold in May–June. In Shanghai, spring and autumn cultivation mainly uses the “Black Eye” variety from Northeast China (the hilum is light coffee-colored when young, black when mature), with large, slightly chewy beans.
Fresh green soybeans cook easily and have good texture. When purchasing, check if the pods are fresh—the surface hairs should be shiny. Fresh pods are firm, with 2–3 beans per pod. Beans should be green or light green, covered tightly by semi-transparent seed coats (white membrane around seeds); pressing them should yield juice. Unfresh soybeans are often soaked in water; if pods turn yellow, hairs dull, pods crack easily, and beans separate from seed coats upon opening, they are no longer suitable for fresh consumption.
When selecting yardlong beans, choose bright green pods that are firm. When broken, the cross-section should show solid pod walls with no gaps between beans and pod walls, and minimal fibrous strands. If the surface develops brown spots during storage, it indicates aging, high fiber content, dehydration, and poor quality. Some new varieties from northern regions are now available—about 20 cm long, flat, 2–3 cm wide, tender and flavorful.
For cowpeas, long cowpeas have thick flesh, tender and crisp. Lighter white-green pods are more tender than dark green ones. Choose pods with thick, firm flesh and no visible seeds—these are fresh. If pods and seeds separate, and shells become soft, the cowpeas are old and unsuitable for cooking. For pickling, select thin, hard-textured cowpea varieties.
Special note: Yardlong beans and flat beans contain toxic substances—saponins and phytohemagglutinin—which must be destroyed by high heat. Cook thoroughly until fully heated to eliminate toxicity. Otherwise, they may cause vomiting, nausea, abdominal pain, dizziness, and other toxic reactions.