Prediction of quality in protein concentrates by laboratory procedures involving determination of soluble nitrogen

Abstract

109 ConclusionsThe synthetic chelating agents used were resistant to nitrification in soils. Application of the acid chelates to soil can considerably modify the concentration of Under the conditions of the experiments described the mineral composition The effect on nutrients in plants. of cabbage plants was considerably more influenced than that of wheat plants. metal concentrations was more marked under alkaline than under acid soil conditions. AcknowledgmentPh.D. in the University of London.This work forms part of a thesis submitted by one of the authors (I. A.) for the degree of Wye College Nr. Ashford Kent

Comparative feeding value of expeller-processed undecorticated and decorticated cottonseed cakes for growing chicks

“…Free-gossypol content and nitrogen solubility in sodium hydroxide are known to be higher in pre-pressed solvent-extracted or direct solvent-extracted cottonseed meal than in the expeller-processed cake and this difference is a direct reflexion of variable heat and pressure generated during oil extraction (Altschul et al 1958). Nitrogen solubility in sodium hydroxide has been used as an index of protein quality and the meal having more than 70 % solubility is accepted as a good quality meal (Lyman, Chang & Couch, 1953;Barnes & Woodham, 1963), although many workers refute this concept (Eagle et al 1956;Eagle & Davies, 1957). In the present study no such relationship was observed between nitrogen solubility and chick growth.…”

“…Available carbohydrate was determined chemically (Clegg, 1956). Nitrogen solubility in acid (6N-HC1), alkaline (0-02 N-NaOH) and saline (0-5 N-NaCl) solutions was also determined (Barnes & Woodham, 1963).…”

Cottonseed Meal for Poultry: from Research to Practical Application

“…Many additional studies in which a correlation between bird response and nitrogen solubility in alkali ranging from excellent to fair have been reported (Condon et al, 1954;Chang et al, 1955;Grau and Zweigart, 1955;Sasser, 1956;Baliga and Lyman, 1957;Eagle and Davies, 1957;Boyne et al. 1961;Duckworth et al, 1961 ;Stephenson and Greene, 1962;Miner, 1962;Mann et al, 1962;Barnes and Woodham, 1963). Conley et al, (1955) reported a poor correlation between nutritive value and nitrogen solubility when the solubility of the meal exceeded 80 per cent.…”

“…Cottonseed meals have been subjected to several other chemical methods designed to measure protein quality. These include solubility in hydrochloric acid (Boyne et a/., 1961;Anwar, 1962;Barnes and Woodham, 1963), globulin fractionation (Anwar, 1962) and solubility in sodium chloride Condon et al) 1954;Boyne et a/., 1961 ;Anwar, 1962;Barnes and Woodham, 1963).…”

“…These methods include (a) "gross protein value" (Anwar, 1960(Anwar, , 1961(Anwar, , 1962Duckworth er al., 1961;Boyne et al, 1961;Barnes and Woodham, 1963), (b) microbiological with Tetrahymena pyrformis (Stott et al, 1956;Boyne et a/., 1961), (c) enzymatic release of amino acids (Ingram et al, 1950;Jonsson, 1961 ;Ascarelli and Gestetner, 1962) and (d) carcass retention of nitrogen, referred to as "net protein value" (Fisher et a/., 1962) or "net protein utilization" (Braham et al, 1963).…”