Vitamin-Bearing Plants

plants that form and store vitamins in quantities sufficient to serve as industrial raw materials for the manufacture of pure preparations or vitamin concentrates or of sources from which human beings and farm animals can obtain vitamins. Vitamin-bearing plants also include those that form substances containing the physiologically active part of vitamins, the so-called provitamins, which the living organism converts to vitamins. For example, plants cannot serve as direct sources of vitamin A, but they store its provitamin, carotene. Plants do not form vitamins of the D group, but ergostearins are widely found in the plant world; they are sources of these vitamins in animals and man and provide them artificially. Vitamins are formed basically in plant cells; in the higher plants their primary synthesis occurs in the green leaf. The majority of vitamins are found in almost all plants, although in various organs and in varying quantities; some vitamins are found only in certain plant species.

Carotene (provitamin A) is synthesized by almost all higher plants. The basic sources of carotene for humans are the red and yellow fruits of root crop plants. For example, the roots of red carrots contain up to 18 mg percent carotene, and less complex technology is required to extract it than to extract carotene from leaf material. The most valuable sources of nutritionally available provitamin A are parsley (leaves), leaf cabbage, spinach, sorrel, spring onions, celery, green peas, green peas from beans and kidney beans, sweet green peppers, tomatoes, pumpkins, apricots, plums, sweet-brier (the flesh of the fruits), sea buckthorns, and bilberries. Fodder plants with high carotene content include alfalfa, clover, wheatgrass, meadowgrass, and timothy. Carotene is formed in the leaves, roots, and fruits, and in very rare cases in the flowers, as in marigolds.

B-complex vitamins are also widely found in the plant world. In industry the main raw materials for the preparation of vitamin B₁, B₂, and PP concentrates are yeasts and the seed embryos of cereal grains. Large quantities of vitamin PP are found in edible mushrooms, which are second only to yeasts in this property. Vitamin B₆ and biotin are obtained commercially from bakers’ and brewer’s yeast. Yeasts contain folic acid, too, which is also found in large quantities in the leaves of many plants. Pantothenic acid is found in bran, yeasts, and cauliflower. Vitamin B₁₂ accumulates in bluegreen algae, actinomycetes, and in some bacteria, and vitamin B₁₅ is found in the seeds of many plants.

Vitamin C (ascorbic acid) is formed in almost all higher plants, mainly in the leaves but to a lesser degree in the fruits, roots, and stalks. Sometimes there is significantly more vitamin C in the fruits than in the leaves of a plant (some species of sweetbrier, actinia, and black currants and unripe walnuts). Vitamin C is usually absent from mature seeds, but it is present in their sprouts. The basic food sources of vitamin C are vegetables and fruits, especially potatoes; the tubers contain a small amount of vitamin C, but they are used regularly in the diet. The fruits of several species of sweetbrier are used to obtain pure commercial vitamin preparations, and concentrates are obtained from sweetbrier fruits, unripe walnuts, red peppers, black currants, and sea buckthorns.

Stearins (provitamin D) are found in almost all plants; they compose 0.5-0.6 percent of vegetable oils. Yeasts and mushrooms are the basic commercial raw material for obtaining provitamin D, which is converted into vitamin D by the action of ultraviolet radiation. Vitamin E (tycopherol) is found in many plants, especially in the sprouts of seeds of some grains. Vitamin E concentrate is obtained commercially basically from wheat sprouts. It is found in significant amounts in peanuts, peas, corn, soybeans, cottonseed, sesame seeds, and the leaves of head lettuce and tarragon. Vitamin K (phylloquinone) is found in the leaves of cabbage, spinach, chestnuts, carrots, pumpkin, mountain ash berries, and tomatoes. Vitamin P (hesperidin and related rutin) is found in citrus fruits and sweetbrier fruits.