The three most commonly consumed legumes (grams or pulses) in India, black gram (Vigna mungo (L.) Hepper), or urd , green gram (Vigna radiata (L.) Wilczek) or mung, and red gram (Cajanus cajan (L.) Millsp.) or tur, were examined by scanning electron microscopy . Seed coat and internal features were examined to differentiate these legumes from common beans (Phaseolus vulgaris) , adzuki beans (Vigna angu/aris) and lentils (Lens culinaris). Cross-sections of the seed coats of black, green and red gram contained single layers of columnar palisade cells extending as double palisade layers at the hilum regions. The funiculi located above the hila contained storage cells; some cells were possibly collapsed during abscission from the seeds. The seed coat surface of red gram exhib ited randomly distributed pits associated with surface deposits . Red gram exhibit ~ ed promine nt ridges above the hilum. The sub - epider ~ mal regi on of red gram seed coat contained elongated pi llar-shaped cell s, generally called hourglass cells. Pi I ~ lar cells were al so present adjacent to the hilum region of both black gram and green gram seed coats , but were absent in the seed coat away from the hilum region . Starch granules embedded in a protein matrix were observed in the cross-section of cotyledons of each of the grams. Additional characterization of the microstructure of legumes will contribute to seed identification, and aid the understanding of changes that occur with development of the "hard-to-cook" phenomenon and during preparation, processing or cooking of legumes.
Joseph, Enamuthu; Crites, Shelly G.; and Swanson, Barry G.
"Microstructure of Black, Green and Red Gram,"
Food Structure: Vol. 12
, Article 3.
Available at: http://digitalcommons.usu.edu/foodmicrostructure/vol12/iss2/3