Effects of commercial canning on SDS-PAGE patterns of the albumin fraction of four pea sizes

Size has been related with pea seed growth and maturation [1], and it is also considered an important parameter when peas are chosen for canning [2]. Some changes occur in the composition of vegetables during blanching, which are the partial loss of major components [3], that are further reduced during canning, mainly due to leaching into the water used for processing [4]. This leaching can be significant if the brine is discarded and not used as a part of the food consumed, as it is often done with most of canned vegetables [5]. Pea seed is an important source of protein for humans, and it has been suggested [6] that when considering pea seeds protein quality more emphasis should be given to the study of the albumin fraction, because it is the fraction rich in the sulphur amino acids. Although electrophoretic analysis of heat-treated proteins can be considered as time consuming it has been used to monitor changes in specific proteins and mixtures of protein subjected to a variety of heat treatments [7]. In general, heat treatments result in a drastic change in polyacrylamide gel electrophoresis (PAGE) patterns in the presence of the detergent sodium dodecyl sulfate (SDS) by reducing the number of bands compared to untreated samples [8]. The purpose of this study was to monitor changes in the albumin fraction of the protein of 4 sizes of peas in the raw, blanched and canned products, and the can brine solutions, using SDS-PAGE.