Relationship between Food Processing and the Digestibility of the Proteins - Essay Example

Effects of food processing on protein digestibility By: Professor: Class: University: City: State: Date of submission: Effects of food processing on protein digestibility Introduction The aim of the essays is to explore the complex relationship that occurs between food processing and digestibility of the proteins. Food proteins are critical nutrients playing a central to control the textual features of several foods. However, processing of the food proteins could alter its aggregate structure and digestibility with the extent of aggregation during processing depending on the denaturing conditions and the presence of other components of food. Foods components such as sugars and lipids could contribute to glycation in protein and protein cross-linking through Maillard reaction. Moreover, the residues of amino acids of the food proteins might experience chemical modification while processing; as a result, it influences both the nutritional value and structure of the proteins (Better Health Channel, 2016). Through undertaking a proteomic analysis using tendem mass spectrometry, heated protein often, show increment in the hydrothermally induced amino acids modification. Whenever there is availability of glucose and methylglyoxal, there is an increment in the modification of arginine to hydroimidazolone especially with rise in the Maillard reaction. These modifications are likely to change the nutritional quality of the protein. There are beneficial effects of food processing especially on array of the foods with toxic substances and anti-nutrients such as seed foods, cereals, and legumes. In most cases, digestibility improves through fermentation, heating, and soaking. Various processing steps reduce the number of active enzymes inhibitors by extracting and inactivating them. Reduction in the digestibility of the proteins results from the presence of excess heat and exemplification through comparative preparation of ready-to-eat food. Processes Reducing Protein Digestibility During the earlier stages of the reaction and interaction of proteins with different micro-constituents of food during processing, proteins are exposed to different chemicals. Some reaction that involve only proteins results in the formation of racemisation, isopeptides, and lysinoalanine while a reaction that involves proteins and carbohydrates (Maillard reaction) results in the oxidation of the lipids and polyphenols. The common reaction that in most cases takes place during processing of food and storage is Maillard reaction. Unavailability of lysine often occurs due to processing and storing foodstuffs in N epsilon-fructoselysine (FL). In the heat processed proteins, the N epsilon-carboxymethyllysine that is an oxidative degradation product usually occur in variable but insignificant amounts. With its indole-NH-group, the tryptophan has the ability of participating in the Maillard reaction (Tamanna & Mahmood, 2015, 4). These reactions often have impacts on the two components of the protein value: digestibility and biological values. Through modification of the production molecules, the digestibility of proteins reduces. The modification involves blocking of amino acids side-chains and establishment of the cross-links. Processing also leads to the formation of compounds inhibiting the digestive enzymes (Olaluwa et al., 2014, 1996). Advanced Maillard derivative of the lysine could also lead to inhibition of the aminopeptidase. However, the diminishment of the biological value could result if there is loss of essential amino acids and reduction in the specific availability. Proteins in Fabricated Food Structures Besides the role of the proteins as macronutrient, they play vital roles in the formation of structures including the foams and gel networks found in the whipped egg white and protein gels in various cooked meat products. Moreover, proteins also play important role in the emulsification of oils within the sauces including mayonnaise in which there is formation of the interconnectedness that forms an adsorbed coating layer in the oil droplets (Korus, 2012, 679). Partial denaturing and modification make proteins conform to the processed food similar to those found within the processed natural food metrics. In such case, the interaction is complex considering that the ultra-structure of the natural food matrix could undergo compartmentalization and breakdown during cooking to some varying extents. The modification types that food proteins could undergo during the processing involve unfolding and aggregation of proteins besides the chemical modification. These types of modification tend to have effect the digestion stability leading to formation of various allergens presented to the immune system concerning elicitation and sensitization (Poel, Prestløkken & Goelema, 2005, 632). The level to which the proteins are affected through various processing conditions depends on the process since denaturing of the proteins require the availability of water as proteins become more thermostable within the low ware systems. Other factors that could affect the patterns and the kinetics of the proteins denaturing and aggregation include the presence of temperatures and ingredients such as sugars and fats. The widely used food protein for the study is globular protein β-lactoglobulin (β-Lg) which one of the major components of the milk and majorly used in the isolation and concentration of proteins. The β-Lg is 18,400 dalton retinol that binds the protein with the β-barrel structure feature of the lipocalin superfamily stabilized by two intra-molecular disulphide bonds together using a single free cysteine residue: (Cys106- Cys119, and Cys66- Cys160). When heated, the β-Lg tends to dissociate into various monomers, which then unfolds partially before it associates into the threadlike aggregates, which at high level of concentration would lead to the formation of string-like aggregate forming the gel networks (Jaworska, Bernaś & Biernacka, 2011, 247). The unfolding reveal that the buried Cys121 has the ability of catalyzing the disulphide interchange for the formation of non-native monomer that Cys119 is exposed allowing the protein to link to the other food proteins including caseins. Such ability of the proteins in forming the intermolecular disulphide cross-links tends to affect the mechanical stability of the gels, which makes them strong. Unfolding and aggregation of proteins could be induced through mixing and shearing occurring in various food processing and adsorption processes involved in the stabilization of various interfaces found within the food foams and emulsion (Hayes & Brunton, 2011, 381). Therefore, it appears that the adsorbed proteins tend to undergo limited unfolding at the interfaces; however, they do not form the aggregated structures at the interface akin to the semi-2-dimensional gel network, which could as well be interconnected through the disulphide bonds. These structures could have impact on the allergen structure in a manner pre-determined through the protein structures although the process type and addition of the other ingredients or pH could alter the effects. Effects of Food Protein Processing On Health Protein is the most reactive of the major food components. While processing the food, the essential amino acids, lysine, methionine, tryptophan, and cystine could react with the other components of food that cause loss of the amino acid bioavailability and to some extent leading to reduction in the digestibility of the whole molecules of protein. Most processed foods have been compromised through addition of the hormones, additives, preservatives, chemical and heat treatments, and genetic materials, which to some extent alter or destroy the natural health of the proteins. It is vital to avoid non-organic pasteurized and homogenized milk products since most commercial dairy farms tend to inject the cows with the recombinant bovine growth hormone (rBGH) made from the genetically modified organisms (GMO) (Hayaloglu & Güven, 2014, 110). Moreover, it increases the level of milk production but leads to sickening of the cow through increasing the udder infections and lameness. Proteins within the pasteurized milk have been altered due to high heat applied and the beneficial digestive enzymes have been destroyed. In absence of such beneficial enzymes, milk is difficult to digest resulting in lactose intolerance. According to the International Agency for Research on Cancer (AIRC), processed meat is carcinogen. People consume several processed meat. For the people, the risk of developing a colorectal (bowel) remains small considering their consumption of the processed meat; however, the risks level tend to increase with the amount of meat that people consume. Some of the substances used in smoking process in preserving the meat could lead to the formation of the compounds that cause cancer including the polycyclic aromatic hydrocarbons (PAHs) (Bailly & Guerre, 2009, 102). Furthermore, processing of meat often involves using the nitrates as preservatives in preventing the growth of bacteria and various colouring agents. Nonetheless, the nitrates could lead to the formation of compounds such as N-nitroso compound. The red meat also has numerous irons for the formation of heme iron, which in turn, stimulate the release of N-nitroso compounds within the gut. Cooking methods also play vital role in the promotion of cancer (Morken et al., 2011, 29). Using the high temperature method could lead to formation of more cancer promoting chemicals including heterocyclic amines (HCAs) and the char outside the meat containing PAHs. Conclusion Food proteins often have structure that when exposed to various processes, there could be digestibility problems. Moreover, the proteins are vital in controlling the textural features of other foods; however, processing proteins could lead to alteration of its aggregate structure leading to digestibility problems. The extent of aggregation during the processing of food usually depends on the conditions for denaturing and availability of other food components. Through Maillard reaction, the sugars and lips could contribute in glycation and cross-linking of the proteins. Additionally, processing the proteins could lead to chemical modification of the amino acid residues, which in turn affect both the structure, and nutritional value of the proteins. The essential amino acids, cystemine, metionine, and tryptophan could react with various food components during processing leading to loss of amid acid bioavailability and to some extent leading to reduction in the digestibility of the whole molecule of protein. References Bailly, J., & Guerre, P. (2009). Mycotoxins in Meat and Processed Meat Products. Safety of Meat and Processed Meat, 2(1), 83-124. doi:10.1007/978-0-387-89026-5_4 Better Health Channel. (2016). Food processing and nutrition. Retrieved September 22, 2016, from https://www.betterhealth.vic.gov.au/health/healthyliving/food-processing-and-nutrition Hayaloglu, A. A., & Güven, M. (2014). Nutritional Quality Assessment in Dairy Products: A Perspective. Food Engineering Series, 4(3), 105-123. doi:10.1007/978-1-4939-1378-7_4 Hayes, J., & Brunton, N. (2011). The use of nutraceuticals in processed meat products and their effects on product quality, safety and acceptability. Processed Meats, 3(2), 372-402. doi:10.1533/9780857092946.2.372 Jaworska, G., Bernaś, E., & Biernacka, A. (2011). Effect Of Pretreatments And Storage On The Amino Acid Content Of Canned Mushrooms. Journal of Food Processing and Preservation, 36(3), 242-251. doi:10.1111/j.1745-4549.2011.00580.x Korus, A. (2012). Amino Acid Retention and Protein Quality in Dried Kale ( Brassica oleracea L. var. acephala ). Journal of Food Processing and Preservation, 38(2), 676-683. doi:10.1111/jfpp.12017 Morken, T., Kraugerud, O. F., Sørensen, M., Storebakken, T., Hillestad, M., Christiansen, R., & Øverland, M. (2011). Effects of feed processing conditions and acid salts on nutrient digestibility and physical quality of soy-based diets for Atlantic salmon (Salmo salar). Aquaculture Nutrition, 18(1), 21-34. doi:10.1111/j.1365-2095.2011.00872.x Olaluwa, T. A., Odutola, O., Sunday, O. O., & Anthony, J. A. (2014). Influence of processing methods on mycoflora changes during storage of raw and processed Atlantic horse mackerel (Trachurus trachurus). Afr. J. Biotechnol, 13(19), 1992-1998. doi:10.5897/ajb2014.13712 Poel, A. F., Prestløkken, E., & Goelema, J. O. (2005). Feed processing: effects on nutrient degradation and digestibility. Quantitative aspects of ruminant digestion and metabolism, 4(2), 627-661. doi:10.1079/9780851998145.0627 Tamanna, N., & Mahmood, N. (2015). Food Processing and Maillard Reaction Products: Effect on Human Health and Nutrition. International Journal of Food Science, 2015, 1-6. doi:10.1155/2015/526762 Read More