Effect of Finishing Diet on Physico-Chemical and Lipolytic Parameters and Volatile Compounds Throughout the Manufacture of Dry-Cured Foal “Cecina”

Special Article - Food Chemistry

Austin J Nutri Food Sci. 2015;3(1): 1056.

Effect of Finishing Diet on Physico-Chemical and Lipolytic Parameters and Volatile Compounds Throughout the Manufacture of Dry-Cured Foal “Cecina”

María Gómez, Rubén Domínguez, Sonia Fonseca and José M Lorenzo*

Technological Centre of the Meat of Galicia, Spain

*Corresponding author: Jose M Lorenzo, Technological Centre of the Meat of Galicia, Galicia Street No. 4, Parque Tecnológico de Galicia, San Cibrao das Viñas, 32900 Ourense, Spain

Received: November 22, 2014; Accepted: February 11, 2015; Published: February 12, 2015


The objective of this study was to investigate the effect of the finishing diet (1.5 kg vs. 3 kg of commercial feed) on the physico-chemical, colour, textural and lipolytic parameters and volatile compounds of dry-cured foal “cecina” throughout the manufacturing process. Ripening time significantly affected (P<0.05) all the studied parameters. Finishing diet of foals did not affect (P>0.05) its chemical composition. Considering physico-chemical parameters, some differences were found at several sample points. Higher red colour (a*) (P<0.001) and lower total work (kg⋅mm) (P<0.05) were observed in the 3 kg “cecinas” group at the end of manufacturing process. TBAR´s reached their maximum values after post-salting stage, being these results significantly higher in “cecinas” from foals feed with 3 kg of concentrate. Free fatty acids (FFA) release was significantly higher in “cecinas” from the 3 kg group, especially due to the higher content of oleic and palmitic acid. Finally, the largest amount of volatile compounds was obtained in “cecinas” from the 3 kg group, however, hexanal content was significantly higher on 1.5 group.

Keywords: Foal dry-cured “cecina”; Finishing diet; Physico-chemical parameters; Volatile compounds; Lipolysis


Salting and drying have traditionally been used as common procedures for preserving meats, mainly based on the decrease of water activity. Nowadays, a wide variety of salted, dry-cured meat products are produced from whole meat pieces of pork, beef, goat, venison and horse. The characteristic flavour of these meats is one of the most appreciated attributes for the consumer. “Cecina” is a salted, smoked and dried meat product widely consumed in the northwest of Spain with a very similar manufacture to that used in the production of dry-cured ham. Spanish “cecina” also resembles South African “biltong”, South American “charqui” and Italian “bresaola” [1]. “Cecina de León”, produced from beef, and “Cecina de chivo de Vegacervera”, produced from goat meat, both in the region of León (NW of Spain), have been awarded the Protected Geographical Indication (PGI) label and a guarantee mark, respectively.

Horsemeat has been historically obtained from animals that were slaughtered at the end of their working lives [2], hence the poor organoleptic and nutritional quality of this meat [3]. Consumption of horsemeat has increased in recent years in some European countries maybe due to the interest of consumers on tasting new meat products [4]. However, most of the horsemeat produced in Spain is exported to Italy and France since its consumption is still not comparable to other meat such as beef, chicken and pork [5]. Foal meat is characterized by low fat and cholesterol contents while it is rich in iron [6]. Foal meat has also a positive dietetic fatty acid profile, with a high content of unsaturated fatty acids in relation to saturated acids, and contains a greater proportion of components from the a-linolenic fatty acid family [5,7,8]. Nevertheless, it has been reported that meat quality of different animal species can be influenced in an intramuscular level by finishing diet [9-11], leading to final variations on colour traits, tenderness and fatty acid profile, and therefore conditioning consumer acceptability [12]. Studies concerning physico-chemical and sensorial characteristics of dry-cured foal “cecina” has been reported [13], as well as some works evaluating the effect of the finishing diet on fresh horsemeat quality [14,15]. However, to our knowledge, there is no information about how the finishing diet supplied to the animals influences the quality of “cecina” manufactured from foal meat.

Therefore, the aim of this work was to investigate the effect of the finishing diet of foals slaughtered at 15 months in the physicochemical, colour and textural properties, lipolysis and volatile compounds of dry-cured foal “cecina” throughout the manufacturing process.

Materials and Methods

Animal management and foal “cecina” manufacture

For this study, twenty one foals of the “Galician Mountain” breed were used. Animals were obtained from the experimental herd of Agricultural Research Centre of Mabegondo (Marco da Curra, A Coruña, Spain). The majority of the foals were born between April and May 2010. Animals were reared with their mothers on pasture and were allowed to suck freely. Foals were weaned when they were 6-8 months old. The finishing period was 4 months (from April to August). Then, foals were fed with concentrate and pasture in the best conditions of amount and quality. Foals were fed with two different amounts of concentrate (1.5 kg of fodder/foal-day and 3 kg of fodder/ foal-day).

Forty knuckles with an average weight of 2.83 ± 0.50 kg, were selected and the “cecinas” were manufactured as described by Lorenzo (2014) [13]. Samples were taken as fresh, after salting, after post-salting and after 60 and 120 days of drying–ripening. At each sample point, four pieces were analysed.

Chemical composition

Moisture, fat, protein (Kjeldahl N × 6.25) and ash were quantified according to the ISO recommended standards [16-19]. Total chlorides were quantified according to the Carpentier–Vohlard official method [20]. Results were expressed as g/100 g of dry matter.

pH, water activity, TBARs values and colour parameters

The pH of samples was measured using a digital pH-meter (Thermo Orion 710 A+, Cambridgeshire, UK) equipped with a penetration probe. Water activity was determined using a Fastlab (Gbx, Romans sur Isére Cédex, France) water activity meter, previously calibrated with sodium chloride and potassium sulphate. Colour measurements were carried out using a CM-600d colorimeter (Minolta Chroma Meter Measuring Head, Osaka, Japan). The homogeneous mass obtained from the grounded of each sample was measured three times for each analytical point. CIELAB space: lightness (L*), redness (a*) and yellowness (b*) were obtained. Before each series of measurements, the instrument was calibrated using a white ceramic tile. Lipid oxidation was assessed in triplicate by the 2-thiobarbituric acid (TBARs) method of Vyncke (1975) [21] with the modification that samples were incubated at 96°C in a forced oven (Memmert UFP 600, Schwabach, Germany). Thiobarbituric acid reactive substances (TBARs) values were calculated from a standard curve of Malonaldehyde (MDA) and expressed as mg MDA/kg sample.

WB and texture profile analysis

Seven meat pieces of 1 × 1 × 2.5 cm (height × width x length) were removed parallel to the muscle fibre direction and were completely cut using a Warner-Bratzler (WB) shear blade with a triangular slot cutting edge (1 mm thick). Maximum shear force, shear firmness and total necessary work performed to cut the sample were obtained. Textural profile analysis (TPA) test measured in a texture Analyser (TA.XT.plus of Stable Micro Systems, Vienna Court, UK) by compressing to 60% with a compression probe of 19.85 cm 2 of surface contact at a compression speed of 3.33 mm/s and recording speed was also 3.33 mm/s. Hardness (kg), cohesiveness, springiness (mm) and chewiness (kg*mm) were obtained using the computer software (Texture Exponent 32 (version, Stable Micro Systems, Vienna Court, UK).

Free fatty acid content

Total intramuscular lipids were extracted from 50 g of each minced sample, according to Folch et al. (1957) [22] procedure. Free fatty acids were separated from fifty milligrams of the extracted lipids using aminopropyl (NH2) mini-columns as described by García- Regueiro et al. (1994) [23]. This fraction was transesterified with a solution of boron trifluoride (14%) in methanol, according to Carreau and Dubacq (1978) [24] and the fatty acid methyl esters (FAMEs) were stored at -80°C until chromatographic analysis. Separation and quantification of FAMEs was determined following Lorenzo (2014) [13].

Volatile compounds

The volatile compounds profile was studied in dry-cured foal “cecinas” taken at the end of the ripening period. The extraction of the volatile compounds was performed using Solid-Phase Microextraction (SPME). A SPME device (Supelco, Bellefonte, PA, USA) containing a fused-silica fibre (10 mm length) coated with a 50/30 mm thickness of DVB/CAR/PDMS (divinylbenzene/carboxen/ polydimethylsiloxane) was used for HS-SPME extraction. Separation and quantification of the volatile compounds was determined following Lorenzo (2014) [13]. Results for each volatile compound were expressed as AU (area units) x106/g dry matter.

Statistical Analyses

All statistical analysis was performed using SPSS package (SPSS 19.0, Chicago, IL, USA). A one-way analysis of variance (ANOVA) was carried out for all variables considered (processing time and finishing feed). A Duncan´s test was performed to compare the mean values for processing time at a significance level of P<0.05. Analysis of variance using the General Linear Model (GLM) was performed, including in the model the variables finishing feed and processing time, to show the significance of time of processing. Correlations between variables were determined by correlation analyses using the Pearson’s linear correlation coefficient.

Results and Discussion

Chemical composition and physico-chemical parameters

The evolution of chemical composition during the manufacture process of “cecina” from foals fed with two different amounts of concentrate is shown in Table 1. Fresh knuckles showed an average moisture content about 76%. This content significantly decreases (P<0.001) throughout the manufacturing process reaching mean values of 40% after 120 days of dry-ripening, similar to that found in foal “cecina” [13] and in beef “cecina” [25]. Nevertheless, these moisture values were slightly lower than those reported in other beef “cecina” studies [26,27]. Intramuscular fat and protein contents (% of DM) were significantly (P<0.001) affected by processing time, increasing (from 1.77% in the fresh piece to 2.9% after 120 days of ripening) and decreasing (from 86.5% in the fresh piece to 79.2% after 120 days of ripening), respectively. Ash content, due to the incorporation of NaCl during salting stage, significantly increased (P<0.001) from mean values of 9% in fresh knuckles to values around 16% for the rest of the studied stages. NaCl (%DM) increment occurred during the whole process, but especially after salting, with an increment over 7%. As a result of salt diffusion, NaCl content increased to reach the final values of 11.47%. The NaCl content resulted inversely correlated with moisture content (r=-0.748, P<0.01) and positively with ash content (r=0.808, P<0.01). Final values of NaCl were slightly lower than those described on a previous study carried out in our laboratory (between 12-13%) [13]. Even though the salting time was exactly the same in both works (0.25 days/kg), the samples of the current study (where concentrate was used in the finishing diet) presented a higher fat content (2.8% vs. 1% in the present study and in Lorenzo, 2014 [13], respectively). As a result, a lower penetration of salt through the pieces was obtained due to the lower diffusion coefficient of salt in the fat than in the lean tissue [28]. Similar NaCl contents were found in beef “cecina” (around 8%) by García et al. (1997) [25] and Molinero et al. (2008) [26], while Molinero et al. (2008) [27] obtained higher contents (around 14%). A few significant differences (P<0.05), and only at the beginning of the manufacture process, were found between finishing diets for moisture, fat and ash content. These differences were also reported when longissimus dorsi (LD) muscle of these animals was studied [14].