An Alfalfa Protein Concentrate from Four Cultivars at Three Growth Stages1
- W. R. Kehr,
- R. L. Ogden and
- L. D. Satterlee2
New sources of high quality protein are needed for human consumption. Alfa fa (Medicago sativa L.) is well known for its high yield of protein. Knowledge of genetic variation for protein concentrate yield among cultivars is needed.
The alfalfa cultivars ‘Dawson’, ‘Kanza’, ‘Team’, and ‘Weevlchek’ were planted in field plots at the Mead Field Laboratory, Lead, Nebr., in 1972. Forage of the cultivars was harvested and sampled as three growth stages, bud, one-tenth bloom, and full bloom, in the first and second cuttings of 1973. Forage samples were used for chemical analyses of fresh forage, pressing juice in the laboratory, protein extraction, and subsequent chemical analyses. The purposes of the study were to determine the yield of an alfalfa protein concentrate (without chloroplasts) (APC) from four cultivars at three growth stages, the forage yield and quality of fresh forage, and to determine the recovery and nutrient levels in the residue of processed forage.
The cultivars did not differ in dry matter,protein,and carotene levels of fresh forage at any growth stage in either the first or second cutting. The percentage of protein in APC's did not differ among cultivars at any growth stage in either cutting and averaged 76%. Forage and APC yields differed among Cultivars. The lowest forage and APC yields were obtained from Kanza. About 1% of the fresh weight of alfalfa was recovered as APC. APC yield averaged about 200 kg/ha over cultivars and cuttings. APC recovery percentages differed among cultivars and the lowest recovery was from Kanza. Protein recovery decreased as physiologic mauturity increased.
At one-tenth bloom, average protein level of fresh forage was 18.6% compared with 16.4% protein in the residue after pressing (juice extraction), a 12% reduction due to processing. Average carotene level of fresh forage was 190 mg/kg, and carotene level of the residue was 145 mg/kg at one-tcnth bloom, a 24% reduction.
The yield of an alfalfa protein concentrate that contained 76% protein, potentially suitable for human consumption, vaned among cultivars as shown in this preliminary study.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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