Preparation and characterization of films from pea protein.

The conditions for protein film preparation from an alkaline dispersion of a pea protein isolate were investigated in the presence of polyols as plasticizers. Mechanical and barrier properties of resulting films were studied as a function of protein dispersion conditions, protein and plasticizer concentrations and ratios, chain length of the plasticizer, and pH and composition of the alkaline medium. Neither the mode of protein hydration nor the pea isolate origin had a significant effect on the mechanical properties of pea protein films. However, increasing the plasticizer chain length induced slightly higher surface hydrophobicity but poor mechanical properties. Addition of monoglycerides to film-forming solution allowed a significant improvement of the films during aging. Both tensile strength and surface hydrophobicity increased when ammonium hydroxide was used as protein dispersing agent instead of sodium hydroxide.

[Aflatoxin inactivation after ammonia treatment. In vitro studies on detoxified peanut meals]. / Inactivation des aflatoxines par traitement a l'ammoniac. Etudes in vitro de tourteaux d'arachide détoxiqués.

The maximum allowable tolerance of aflatoxins in animal feeds is becoming lower and lower, and it is obvious that the fairly high level of aflatoxin B1 found in almost all peanut meals in recent years restricts this protein source for use in the diets of most animal species. Among the different chemical methods for aflatoxin inactivation, treatment by gaseous ammonia under a pressure of 2 to 3 bars, appears a very attractive solution because it may be achieved by a fairly easy and rapid procedure. This treatment markedly reduces--up to 95 p. 100--the aflatoxins content of the meal. An increase in the nitrogen content, mainly in the non protein form, is observed. Ammoniation has no adverse effect on in vitro pepsin digestibility and even improves the sensitivity of the meal towards proteases. It slightly reduces protein deamination in the artificial rumen and nitrogen solubility in a buffer solution at pH 7,5; these effects seem to be favourable for the utilization of the treated meals by rumiinants. The amino acid compostion of the meal is not significantly changed, particularly with regard to total and available lysine. However, cystine undergoes partial destruction; but this loss could be counterbalanced by a supply of synthetic methionine.