Use of dietary rosemary diterpenes to inhibit rancid volatiles in lamb meat packed under protective atmosphere

Abstract

The objective of the present study was to determine the inhibitory effect of dietary rosemary diterpenes on the formation of the volatile organic compounds (VOCs) responsible for rancid flavour in raw lamb meat. The lamb diet was supplemented during the fattening stage with two levels (200 and 400 mg/kg feed) of a dietary rosemary extract (DRE) containing carnosic acid and carnosol (1 : 1, w/w). The formation of VOCs (determined by headspace solid-phase microextraction at 40°C and MS) and odour deterioration (assessed by quantitative descriptive analysis) were monitored in meat fillets (longissimus dorsi-lumborum muscle) packed in a 70/30 O 2 /CO 2 protective atmosphere and kept at 2°C for up to 14 days. The raw meat odour deteriorated under pro-oxidizing conditions due to the development of an incipient rancidity caused by the formation of volatiles from lipid oxidation. A total of 46 volatile compounds were determined in lamb headspace: 18 aldehydes, seven alcohols, seven organic acids, six ketones, four furan compounds, two benzene compounds, one ester and one terpenoid. The use of DRE contributed to inhibit VOC formation and rancidity. Heptanal, octanal, nonanal and 2-pentyl-furan were the only VOCs affected ( P < 0.05) by the diet at any storage time. In general, VOC formation rate during storage was lower ( P < 0.05) in the meat from lambs that received a diet supplemented with 400 mg DRE/kg feed than in the meat from lambs receiving no dietary supplementation. VOC inhibition was less effective when the dose of DRE was reduced to 200 mg/DRE kg, although it depended on the VOC analysed. The intensity of rancid odour correlated ( P < 0.05) with the values of 43 of the 46 VOCs. The highest coefficients were obtained for octanol and octanal ( R > 0.75; P < 0.001), although similar values were obtained for the coefficients of a large number of carbonyl, alcohols and furan compounds, among other volatiles, which can be considered molecular markers of rancidity in raw lamb meat. Principal component analysis confirmed that the differences in the VOC profile make it possible to identify whether or not samples have been reinforced with dietary rosemary diterpenes. Thus, VOC profiling can be regarded as a useful tool for assessing the dietary treatments used in sheep to improve the oxidative stability of lamb meat.

Effect of Wine Lees as Alternative Antioxidants on Physicochemical and Sensorial Composition of Deer Burgers Stored during Chilled Storage

“…A high level of PUFA was found in the intramuscular fat of deer meats, and autoxidation could be initiated more readily in this type of meat [42]. Some authors observed aldehydes inhibition in different meat products using natural antioxidants [43,44]. In our case, the total quantity of aldehydes increased in control samples during chilled storage in MAP; however, in the burgers with lees, it remained constant (except in the case of the Lpb sample).…”

Influence of the Production System (Intensive vs. Extensive) at Farm Level on Proximate Composition and Volatile Compounds of Portuguese Lamb Meat

“…Concretely, octanal was the one that was found in greater presence in the lambs reared under intensive conditions (2.30 AU × 10 4 /g fresh meat), while it did not appear in the lambs reared extensively. This fact could indicate that intensively-reared lambs may have a greater intensity of rancid odor, since previous studies have found that octanal is the aldehyde that presented the highest correlation with this parameter in lamb meat packed under a protective atmosphere [ 76 ]. On the contrary, nonanal was only detected in extensively-reared lambs since it is the aldehyde that appears in the highest concentration in the meat of these animals (2.56 AU × 10 4 /g fresh meat), after 2-propenal with a concentration of 4.04 10 4 /g fresh meat, which would provide a plastic and soapy aroma [ 77 ].…”

“…These differences could be related to the possible variability of the fatty acid profile of lambs [ 88 ] because the main origin of esters is the esterification of carboxylic acids [ 89 ]. Despite the differences, previous studies have shown that the contribution of esters to the aromatic profile of lamb meat may be low [ 68 ]; several authors did not even detect these compounds [ 17 , 81 , 90 , 91 ] or detected a low number of esters [ 37 , 76 , 87 , 88 ]. Therefore, although the fraction of esters to the total volatile compounds was relatively high (3.35 in intensively-reared lambs and 3.51% for lambs reared under extensive conditions) ( Figure 1 ), their presence may not contribute to the overall aroma of the lamb meat.…”

Differences in Consumer Preferences for Lamb Meat before and during the Economic Crisis in Spain. Analysis and Perspectives

“…It seems paradoxical that given the growing concern for food safety, the packing attribute is only fifth in the order of importance among lamb meat consumers, with similar results in both 2004 and 2014, since packing serves as a container, protecting the meat from physical and chemical deterioration [ 44 ] and environmental contamination [ 45 ], and favoring longer shelf life as a result of various strategies, such as controlling temperature and moistness, adding different products [ 46 ] and oxygen removal, or a combination of these. Packing is thus a key element in the guarantee of quality and food safety [ 47 ].…”