Aspects of physical and chemical alterations to proteins during food processing – some implications for nutrition

Abstract

In this paper, we give an overview of our research exploring the impact of physical and chemical processing on food proteins. There are three themes, applied to the proteins of wheat, soya, egg and dairy foods. Firstly, the impact of the Maillard reaction on food proteins is discussed, with a particular focus on how the reactions might be harnessed to manipulate food texture. Secondly, the potential of enzymatic protein-protein crosslinking is considered, especially the enzyme transglutaminase. Thirdly, the broader question of how the aggregation of proteins within a food is altered by chemical and physical modification and how, in turn, this might impact on the overall nutritional quality of the food is considered.

Antioxidant and chelating capacity of Maillard reaction products in amino acid‐sugar model systems: applications for food processing

“…Furthermore, the components of different foods, in particular sugars and amino acids, may in some cases generate MRP with negative effects on human health and result in anti‐nutritional properties, such as loss of essential amino acids, reduced availability of some minerals and formation of mutagenic or carcinogenic compounds (acrylamide) …”

“…In most cases, these effects are also accepted by consumers, although some aromatic substances and brown compounds may not be desired in certain foods. 12 Furthermore, the components of different foods, in particular sugars and amino acids, may in some cases generate MRP with negative effects on human health and result in anti-nutritional properties, such as loss of essential amino acids, 13 reduced availability of some minerals 14 and formation of mutagenic or carcinogenic compounds (acrylamide). 15,16 In recent years, research on MRP has also focused on their relationship with bioactive properties of foods, such as antioxidant capacity 17 -20 and chelating activity, 21,22 in addition to the antimicrobial, 23,24 anti-inflammatory, 25 prebiotic 26 and antihypertensive 7,19 properties of foods, among others.…”

Effects of Toasting Time on Digestive Hydrolysis of Soluble and Insoluble 00‐Rapeseed Meal Proteins

“…The k after toasting for 120 min was approximately 2-fold lower compared with the k of the untoasted RSM (6.8E−05 vs. 3.4E−05 /M×s, respectively). The decrease in k was probably related to the restricted enzyme accessibility for proteolysis due to protein aggregation or chemical protein modifications [8]. Increasing the toasting time caused a linear (P = 0.006) increase in the DH max of RSM (Table 2).…”

“…The rate of hydrolysis of the insoluble protein fraction linearly decreased by more than 60% when comparing the untoasted to the 120 min toasted RSM. Increasing the toasting time elicited the formation of Maillard reaction products (furosine, N ε -carboxymethyl-lysine and N εcarboxyethyl-lysine) and disulfide bonds in the insoluble protein fraction, which is proposed to explain the reduction Chemical and physical modifications can impair the accessibility of proteins for enzymatic hydrolysis [8]. The proteases in the pancreatic secretions at the small intestine are highly specific.…”

Of proteins and processing: mechanisms of protein damage upon rapeseed processing and their effects on nutritional value

“…It must be considered that structural changes per se (e.g. protein aggregation) and chemical changes due to Maillard reactions may occur simultaneously (66) and that the effects of both on proteolysis might be confounded.…”