• Korean Journal of Food Science and Technology
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• v.2 no.2
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• pp.17-25
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• 1970

Juice were extracted from fresh leaves of 70 species of plants growing in Korea by mincing and pressing the resulting pulp through a cotton cloth. Leaf protein concentrates could be prepared from many species of land and water plants that are at present economically unimportant. The choice of plants is of considerable important. Total-N, protein-N and pH determinations were made on the extracts, and total-N remaining in the fibre were calculated. Leaf protein concentrates were precipitated from the extracts at $75{\sim}80^{\circ}C$, and analysed total-N as protein-N of products. The present paper deals with the calculated yields of leaf protein concentrates from various plants, relations between yield of leaf protein concentrates and total-N of leaves, or pH of extracts, and the amino acid compositions of leaf protein concentrates. Results are summarized as follows. 1. Spinach and radish were the best sources of easily extractable, but good results were also obtained with indian mustard, kail, chenopod, red bean, cucumber, squash, houndberry, white flowered gourd, potato, Humulus japonicus, arrowroot and soybean as a good resources for the production of leaf protein concentrates. 2. In general, the greater the protein content of leaves the greater the yield of leaf protein concentrates. However, there are some plants difficult to make a adequate protein extraction by a simple mechanical process. 3. It was to be expected that leaf protein concentrates would be more extractable with the higher pH of extracts. There were a poor yield of the leaf protein concentrate in the pH values lower than 5.50 of the first extracts. 4. Protein content of the leaf protein concentrate shows marked differences, depending on species and season. It ranged between 29 to 80% of protein contents. However, the majority of plants yielded products containing more than 50% of protein. Products containing more than 75% of protein were obtained from two species of radish and indian mustard. Cabbage and Digitaria sanguinalis cilialis (summer) made products containing 29 to 32% of protein. 5. The amino acid composition of leaf protein concentrates was not greatly altered by species of plants. On an amino acid compositional basis, the leaf protein concentrate has a favorable balance of essential and non-essential amino acids, the only exception being methionine, which was usually low in all cases.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.26-37
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• 1987

This studies were conducted to investigate pathgenicity and host range of Colletotrichum dematium isolated from anthracnose of pepper, and phytoxicity of its culture filtrate and the partially purified toxin. The results obtained were as follows. 1. Investigation on the host range of C. dematium has revealed that pepper as well as soybean, tomato, spinach, and beet were highly susceptible, egg plant and water melon were moderately susceptible and stone leek was slightly suceptible, but no symptoms were produced on carrot, tabacco, cucumber and melon. 2. The culture filtrates of C. dematium in Czapeck dox liquid media were toxic to leaves of pepper and caused necrosis and wilting of the plant. The toxicity of culture filtrates was most active at 15 days after fungal growth in Czapeck dox liquid media and the toxin productivity in still culture was higher than that in shaking culture. 3. The partially purified toxic substance was isolated from the culture filtrates by the acetone precipitation method. When cuttings of various pepper cultivars were placed in the toxin solutions, suceptible cultivars and resistant cultivars were equally toxic and showed necrosis and wilting of the leaves. 4. Several other plants such as soybean, tomato and carrot were also affected with the toxin solution by shoot cutting bioassay and showed veinal necrosis, leaf spots and wilting of the shoots. 5. The acetone precipitation toxin affected seed germination of pepper, cucumber, sesame and egg plant and inhibited the growth of root and hypocotyl of the seedlings.