Volatile Organic Compounds, Oxidative and Sensory Patterns of Vacuum Aged Foal Meat

Abstract

The study aimed to evaluate the effect of 14-day vacuum aging on the volatile compounds (VOC) profile, oxidative profile, antioxidant enzymes activity, and sensory evaluation in the Longissimusthoracis muscle of foal meat under vacuum aging. Longissimusthoracis (LT) was sampled in 20 mm thick slices, vacuum packed, and stored at 4 °C. Samples were randomly assigned to different aging times (1, 6, 9, 14 days after slaughtering). VOCs, thiobarbituric acid reactive substances (TBARs), hydroperoxides, carbonyl proteins, superoxide dismutase, catalase, and glutathione peroxidase were analyzed, and a sensory test was performed. A nested one-way analysis of variance (ANOVA) was performed for aging time as an independent variable. Significance was set at p < 0.05. The main VOCs originating from cooked steaks were aldehydes, (from 47.18% to 58.81% of the total volatile compounds), followed by hydrocarbons (from 9.32% and 31.99%). TBARs and hydroperoxides did not show variations due to aging (p > 0.05), instead, protein carbonyls showed higher values at the 14th day (p < 0.01). Catalase, superoxide dismutase, and glutathione peroxidase showed increasing values during aging time (p < 0.01). Vacuum aging slowed down lipid oxidation, and protein oxidation was shown to be present. However, the best vacuum aging duration is in the range of 6–9 days from slaughtering, with an improvement of sensory evaluation.

How Volatile Compounds, Oxidative Profile and Sensory Evaluation Can Change with Vacuum Aging in Donkey Meat

“…The total alcohols showed a constant trend, and 1-hexanol was the most abundant. Although other authors observed in horse meat that this compound is the most abundant [ 25 , 54 ], they observed a different trend during the vacuum aging, showing increasing values. These compounds also derive from lipid oxidation, particularly from the degradation of oleic and linoleic acid [ 69 ], and their liberation depends on thermal treatment [ 70 ].…”

“…The most represented aromatic hydrocarbon was the furan, 2-pentyl-, showing more than 85% of the total aromatic hydrocarbons, and it probably affects the statistical differences of the entire VOCs family. In similar studies that were conducted on horse meat vacuum aged, Maggiolino, et al [ 54 ] and Tateo, Maggiolino, Domínguez, Lorenzo, Dinardo, Ceci, Marino, Della Malva, Bragaglio, and De Palo [ 25 ] observed that VOCs formation and trend changed depending on muscle considered. In fact, vacuum aging in Semimembranosus muscle only affected toluene, whereas in Longissimus thoracis muscle the vacuum aging modified the benzene and 3-carene content.…”

“…Linear hydrocarbons identified are the most numerous, although some authors pointed out their unimportant role in meat flavour [ 49 ], but not the most abundant, differently from that found by some authors in beef meat [ 45 ]. As observed in horse meat [ 25 , 54 ], the heptane,2,2,4,6,6-pentamethyl- and the undecane are the most abundant, representing around 20% and 10% of total linear hydrocarbons in cooked donkey meat, respectively. Although it seems that linear hydrocarbons also derived by autoxidation processes, particularly of long-chain fatty acids, are principally formed after lipids thermal homolyses [ 63 ], and therefore after heat treatments, as cooking.…”

“…The very probable lack of oxidative processes on intramuscular fat and fatty acids and, consequently, the probable inactivation of microbial activity and the equal cooking method adopted, can easily explain the absence of variation of total ketones compounds during the aging time. However, is really interesting to observe that ketones formed in donkey meat are more abundant than those that are reported in horse meat vacuum packed [ 25 , 54 ], more than triple, since the acetoin was the most abundant ketones and about four times more than those found in vacuum packed horse meat.…”

“…Meat sensory acceptability may depend on cultural factors, themselves linked to regional customs, particularly for donkey meat. Although it has been extensively studied in different species, focusing on improving meat flavour, sensory profile, and consumer perception, few studies focused on equids meat aging and its effects on sensory and aroma characteristics, and the most of them on horse meat [ 18 , 21 , 22 , 23 , 24 , 25 ], and no one on donkey meat. There is a lack of knowledge on aging technique and their effects on donkey meat characteristics and consumers’ perceiving.…”