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The Maillard Reaction in Meat Flavour Formation: The Role of Selected Precursors
Poster Abstracts
407
The Maillard Reaction in Meat Flavour Formation: The Role of Selected Precursors Linda J Farmer*t, Omiros Paraskcvast and Terence D J Hagan*;*Food Science Division, Dept. of Agriculture for Northern Ireland and, ?The Queen ‘s University of Bevat, Newforge Lone, B e v a t BT9 5PX. UK The volatile compounds which give cooked meat its characteristic aroma and flavour are derived from reactions which OCCUT during cooking. Of these reactions. the Maillard reaction is particularly important for the formation of a range of furanthiolsand disultides which possess distinctive ‘meaty’ odours and very low dour thresholds.’” Studies have indicated that some potential precursors of these dour-impact compounds have a significant effect on the aroma of cooked beef and on some of the volatile products of the flavourforming reactions.’” Further inveStigations of the dfects on volatile compounds have now been conducted. Ribose, ribose-5-phosphate, glucose, glucosed-phosphateand inosine monophosphate were added to raw homogenised beef(2 m o l e s lOOg-’)and equilibrated overnight prior to cooking (lOO°C, 30 min). The volatile compounds were collected on Tenax GC (60°C, 30 min) and analysed by GC-MS. Ribose-5phosphate and ribose &ave the most pronounced effects. However, Werences in the ef€ects of each precursor on the various classes of aroma compounds mean that the quantities of these precursors in the meat may affect the balance of flavour compounds formed. For example, ribose and ribose-5-phosphate reduce the headspace concentrations of the Q to & n-aldehydes, with inosine monophosphate having a lesser &ect yet causing the most suppression of the higher n-aldehydes (e.g., CISand CIS). Ribose-S-phosphate and, to a lesser extent, ribose can cause up to 20-fold increases in some of the sulfur-containingcompounds believed to contribute to meat flavour, such as bis(2-methyl-3-fu1yl) disulfide, 2-methyl-3-methyldithioh and methional. Thus, the quantities of such sugars in raw beef may be a limiting factor for meat flavour formation. Gasser, U.; Grosch, W.(1988). 2.Le6ens.-Unters. Forsch., 186,489. Fanner, L.J.; Patterson,RL.S. (1991). FoodChem., 40,201-205. Mottram, D.S.; Madruga, M.S.(1993). In Trendr in Flavour Research, Maarse, H.,van der Heij, D.G., Eds,Elsevier: Amsterdam, pp. 339-344. Farmer, L.J.; Hagan, T.D.J.; Paraskens, 0. (1996). In Flavour Science: Recent Developments, Taylor, A.J., Mottram,D.S., Eds,Royal Society of Chemistry: Cambridge, pp. 225-230.
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Identification of the Lactosylation Site of p-Lactoglobulin Vincem Fogliano, Simona Maria Monti. Attilio Viswnti, Albert0 Ritieni and Giacomino Randazzo; The University of Naples “FedericoIX“. Dept. of Food Science. Via Universitb 100, 80055, Portici (NA), Italy Different methods have been developed to measure protein-bound lactose; the furosine method, which measures one of the products of the acidic hydrolysis of the Amadori compound, being the most widely adopted. Nevertheless the possibility of developing an immunometrical method able to quantify protein lactosylation with high sensitivityand low cost of analysis suggests that the production of antibodies able to recognize protein-bound laaulosyl-lysmne is worth investigating. Although different groups have obtained antibodies which specifically recognize advanced glycation end products deriving from Maillard Reaction’ or N”deoxylactulosyl-lysine~ none of these can be used in routine milk quality analysis. A different immunological approach would be the use of selected lactosylated peptides as antigens. Ifa significant sequence is injected, the antisera obtained should be able to give a response correlated with the milk’s thermal history. To follow this approach, knowledge of the lactosylation sites of milk protein is essential. Although glycation occurs on all milk proteins, whey proteins are the most reactive. Above 60°C, side chains of B-lactoglobulin (BLG), which are normally buried within the native structure, become exposed,with an increase in their reactivity.’ As few data on lactosylation sites are available: we identified BLG lactosylation sites and raised antibodies against glycated and unglycated peptides containingthese sites. BLG was purified from different heat-treated milks and subjected to partial hydrolysis using Werent pmteases. The resulting peptides were purifiedby reversed-phase HPLC using an Aquapore RP 300 column. The same procedure was repeated on f3LG punfied from raw milk and lactosylated by heating with lactose (5 mglml) at 40°C for 120 min. By comparison of the chromatograms, peptides corresponding to peaks which were affected by thermal treatment were idenaed by N-terminal sequence analysis. 1. Matsuda. T.;Ishiguro. H.;Ohkubo, I.; Sasaki, M.;Nakamura, R (1992). J. Biochem., 111,383-387. Ritieni. A; Marchisano, C.; Peluso, G. et al. (1997). Food Chem., S8,53-58. 2. Fogl~ano,V.; Monti, S.M.; 3. Anema, S.and McKenna. A. (19%). J. Agric. Food Chem. 44.422428. 4. Otani. H.;Hmno, A. (1987). Nippon Chikusan Gakkaiho. 58,472482.
407
The Maillard Reaction in Meat Flavour Formation: The Role of Selected Precursors Linda J Farmer*t, Omiros Paraskcvast and Terence D J Hagan*;*Food Science Division, Dept. of Agriculture for Northern Ireland and, ?The Queen ‘s University of Bevat, Newforge Lone, B e v a t BT9 5PX. UK The volatile compounds which give cooked meat its characteristic aroma and flavour are derived from reactions which OCCUT during cooking. Of these reactions. the Maillard reaction is particularly important for the formation of a range of furanthiolsand disultides which possess distinctive ‘meaty’ odours and very low dour thresholds.’” Studies have indicated that some potential precursors of these dour-impact compounds have a significant effect on the aroma of cooked beef and on some of the volatile products of the flavourforming reactions.’” Further inveStigations of the dfects on volatile compounds have now been conducted. Ribose, ribose-5-phosphate, glucose, glucosed-phosphateand inosine monophosphate were added to raw homogenised beef(2 m o l e s lOOg-’)and equilibrated overnight prior to cooking (lOO°C, 30 min). The volatile compounds were collected on Tenax GC (60°C, 30 min) and analysed by GC-MS. Ribose-5phosphate and ribose &ave the most pronounced effects. However, Werences in the ef€ects of each precursor on the various classes of aroma compounds mean that the quantities of these precursors in the meat may affect the balance of flavour compounds formed. For example, ribose and ribose-5-phosphate reduce the headspace concentrations of the Q to & n-aldehydes, with inosine monophosphate having a lesser &ect yet causing the most suppression of the higher n-aldehydes (e.g., CISand CIS). Ribose-S-phosphate and, to a lesser extent, ribose can cause up to 20-fold increases in some of the sulfur-containingcompounds believed to contribute to meat flavour, such as bis(2-methyl-3-fu1yl) disulfide, 2-methyl-3-methyldithioh and methional. Thus, the quantities of such sugars in raw beef may be a limiting factor for meat flavour formation. Gasser, U.; Grosch, W.(1988). 2.Le6ens.-Unters. Forsch., 186,489. Fanner, L.J.; Patterson,RL.S. (1991). FoodChem., 40,201-205. Mottram, D.S.; Madruga, M.S.(1993). In Trendr in Flavour Research, Maarse, H.,van der Heij, D.G., Eds,Elsevier: Amsterdam, pp. 339-344. Farmer, L.J.; Hagan, T.D.J.; Paraskens, 0. (1996). In Flavour Science: Recent Developments, Taylor, A.J., Mottram,D.S., Eds,Royal Society of Chemistry: Cambridge, pp. 225-230.
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Identification of the Lactosylation Site of p-Lactoglobulin Vincem Fogliano, Simona Maria Monti. Attilio Viswnti, Albert0 Ritieni and Giacomino Randazzo; The University of Naples “FedericoIX“. Dept. of Food Science. Via Universitb 100, 80055, Portici (NA), Italy Different methods have been developed to measure protein-bound lactose; the furosine method, which measures one of the products of the acidic hydrolysis of the Amadori compound, being the most widely adopted. Nevertheless the possibility of developing an immunometrical method able to quantify protein lactosylation with high sensitivityand low cost of analysis suggests that the production of antibodies able to recognize protein-bound laaulosyl-lysmne is worth investigating. Although different groups have obtained antibodies which specifically recognize advanced glycation end products deriving from Maillard Reaction’ or N”deoxylactulosyl-lysine~ none of these can be used in routine milk quality analysis. A different immunological approach would be the use of selected lactosylated peptides as antigens. Ifa significant sequence is injected, the antisera obtained should be able to give a response correlated with the milk’s thermal history. To follow this approach, knowledge of the lactosylation sites of milk protein is essential. Although glycation occurs on all milk proteins, whey proteins are the most reactive. Above 60°C, side chains of B-lactoglobulin (BLG), which are normally buried within the native structure, become exposed,with an increase in their reactivity.’ As few data on lactosylation sites are available: we identified BLG lactosylation sites and raised antibodies against glycated and unglycated peptides containingthese sites. BLG was purified from different heat-treated milks and subjected to partial hydrolysis using Werent pmteases. The resulting peptides were purifiedby reversed-phase HPLC using an Aquapore RP 300 column. The same procedure was repeated on f3LG punfied from raw milk and lactosylated by heating with lactose (5 mglml) at 40°C for 120 min. By comparison of the chromatograms, peptides corresponding to peaks which were affected by thermal treatment were idenaed by N-terminal sequence analysis. 1. Matsuda. T.;Ishiguro. H.;Ohkubo, I.; Sasaki, M.;Nakamura, R (1992). J. Biochem., 111,383-387. Ritieni. A; Marchisano, C.; Peluso, G. et al. (1997). Food Chem., S8,53-58. 2. Fogl~ano,V.; Monti, S.M.; 3. Anema, S.and McKenna. A. (19%). J. Agric. Food Chem. 44.422428. 4. Otani. H.;Hmno, A. (1987). Nippon Chikusan Gakkaiho. 58,472482.