Sensory analysis as a tool to compare imported and local meat in outermost regions of Europe

Abstract

Within the outermost regions of Europe, meat is obtained from two sources: importation and local production. Transportation time is the critical factor that affects imported meat (IM) and carcass quality, whereas local meat (LM) is frequently obtained from regional breeds. The aim of this study, therefore, was to evaluate sensorial differences between IM and LM using the Canary Islands as an example of an outermost region of Europe. Two kinds of sensory analyses were performed: a triangular test with 31 untrained consumers and a descriptive test with a trained 12-member tasting panel. In the triangular test 46.7% of consumers were able to discriminate between the two kinds of meat, and there was higher preference for LM than IM (63.6% vs. 36.4%, respectively). Several sensorial differences between LM and IM were found in aspects such as lamb smell or hardness by trained panel. For this reason this study can be taken as a model to promote LM breeds in order to make them more competitive in markets. However, further studies are needed to analyse carcass and meat quality in order to standardise LM.

Keywords:

• lamb
• meat
• sensory analysis
• local
• imported
• quality

1. Introduction

Importation and local production are the two sources of meat in the outermost regions of Europe. In these regions, imported meat (IM) usually comes from the mainland (Europe or America), and its transportation time is the primary factor that affects carcass and meat quality (Monsón et al. 2005). In contrast, local meat (LM) is usually derived from regional breeds (Gandini and Villa 2003).

The Palmera breed of sheep is located on the Canary Islands of Spain. All Palmera animals are located on La Palma Island, where sheep owners have developed an extensive meat production system centred on this breed. This breed was first described by Delgado et al. (1990) and morphologically characterised by Capote et al. (1993). Palmera sheep are mainly raised for their meat, but 50 years ago ewes were also milked for cheese-making. Carcasses from these lambs are typically available at 5 and 10 kg.

In the last years, demand for meat obtained from organic, natural and biological livestock production systems has increased (Estévez et al. 2003). However, the associated cost of this kind of meat production is typically much higher than those needed to raise animals on feedstuff under intensive conditions. In outermost regions of EU, therefore, many consumers prefer to buy imported lamb meat, rather than the more expensive LM. This tendency has produced an extreme decrease in local animal populations, driving the Palmera breed to the brink of extinction.

Differences between local and imported carcasses and meat quality have been described previously in lamb (Sierra et al. 1992) and beef (Delgado et al. 2005; Moreno-Indias et al. 2011). These analyses indicated that to increase the consumption of local livestock, high-quality meat products must be produced, which can then be sold at more expensive prices than IM.

It has been reported that animals and their products, such as meat, are affected by several factors such as genetic (Yildirm et al. 2009), hormones (Aslaminejad et al. 2010; Liu et al. 2010), stress (Hernández-Castellano et al. 2011) and others. Moreover, in recent years other factors have been studied, including nutrition (López et al. 2010; Montano et al. 2010; Argüello 2011) and ageing time (Priolo et al. 2001; Morales-delaNuez et al. 2009; Merera et al. 2010; Morales-delaNuez et al. 2011), that can dramatically affect meat quality. Throughout the meat-producing industry, the use of energetic feedstuffs to supplement pasture diets for limited periods, or for finishing purposes, is becoming more common. Canary Islands residents buy imported lamb meat that is 6 days old, because that is the time required to transport meat from mainland Europe. In contrast, LM is available in the market only 24-h post-slaughter.

The aim of this study was to evaluate differences between imported and LM from two different carcass weights using a sensory analysis profile in an outermost region in Europe, taking the Canary Islands (specifically La Palma Island) as a model.

2. Materials and methods

2.1. Location of the study, animals, rearing and ageing time

This study was conducted at the Universidad de Las Palmas de Gran Canaria, Canary Islands, Spain. The experimental procedures were approved by the Universidad de Las Palmas de Gran Canaria Ethical Committee. Meat from 40 Infraspinatus muscle and 40 Supraspinatus muscle were taken from 20 Palmera and 20 imported carcasses, being classified each carcass according to their weight in 5- and 10-kg carcasses (10 carcasses per group). LM was obtained from animals that were reared in an extensive production system without dietary supplementation. IM carcasses were directly bought from a representative market in Canary Islands. These imported carcasses were obtained from Castellana breed lambs which were reared under intensive production system and were slaughtered by Valladolid slaughterhouse (Valladolid, Spain). The ageing time was 24 h for LM carcasses and 6 d for IM carcasses (under refrigeration conditions in both cases).

2.2. Sensory analysis

The sensory analyses were performed in a special room following the instructions given by the norm ISO 8589 (2007), according to the guidelines followed by Sánchez-Macias et al. (2012). The first test was a descriptive analysis (ISO 4121, 2003) in which a trained 12-member tasting panel was used. In order to evaluate each sample, a survey was used with the following parameters: appearance, smell, texture, flavour and global appreciation (overall), as has been described by Moreno-Indias et al. (2011). The scale used was of none-normal-much and translated to 0–10 points in order to quantify for subsequent data analysis with the exception of chewings that were quantify as the exact number of chews used to swallow each sample.

A triangle tests to detect small differences that may affect the set of attributes or a particular attribute between LM and IM were performed according to ISO 4120 (2004). Thirty-one untrained consumers who were unaware of the experimental conditions were provided with three samples, and each consumer indicated which one of the samples was different from the other two. At the same time, consumers were asked for the sample with the best score.

Supraspinatus and Infraspinatus muscle were used for triangular and descriptive test, respectively. After removing external fat, the selected muscle was cut into 2×2×1 cm³ pieces, wrapped in aluminium foil, cooked at 200 °C on a double-plate grill until the internal temperature reached 70 °C and then cooked steaks were served warm.

2.3. Statistical analysis

The effects of meat origin (imported vs. local) were analysed using the ANOVA procedure of SAS, Version 9.00 (SAS Institute Inc., Cary, NC, USA). Tukey's test was used to evaluate the differences between groups.

3. Results and discussion

Results of LM and IM descriptive analysis are shown in Table 1. Lamb smell scores were higher in IM than LM (5-kg carcasses), most likely because IM was aged longer. Similarly, Albertí et al. (1997) analysed meat from seven Spanish cattle breeds and showed that smell intensity is highly correlated with ageing time. Reineccius (1994) has suggested that meat smells become more intense with ageing time due to the proteolytic and lipolytic processes accelerate over time. However, when 10-kg carcasses were examined, no lamb smell differences were found. It has been described that the increase of free fatty acid levels as a result of lipolytic enzyme activity is related to an increase of meat smell (Gorraiz et al. 2002); however, this lipolytic enzyme activity decreases as animal became older (Hoffman et al. 1984). As higher-weight carcasses, proteolysis and lipolysis rates are typically reduced by the lower calpain activity (Veiseth et al. 2004). This may explain why no lamb smell differences were found when 10-kg carcasses were compared.

Table 1. Sensory analysis of local meat (LM) and imported meat (IM).

	5-kg carcass				10-kg carcass
	LM	IM	SEM	P value	LM	IM	SEM	P value
Appearance	6.26	6.57	0.27	0.571	6.13	5.46	0.29	0.249
Lamb smell	4.80	6.09	0.28	*	5.98	6.09	0.27	0.846
Strange smell	0.83	0.98	0.23	0.744	0.48	0.65	0.22	0.702
Hardness	5.40	4.48	0.21	*	5.23	4.22	0.21	*
Elasticity	2.92	2.587	0.13	0.194	2.97	2.61	0.14	0.200
Juiciness	2.04	2.70	0.12	**	2.55	2.27	0.11	0.212
Oily	1.78	2.05	0.14	0.313	1.90	2.02	0.13	0.644
Chewing	26.48	23.30	1.41	0.265	25.88	26.78	1.59	0.779
Lamb flavour	4.94	5.59	0.26	0.208	5.48	5.35	0.22	0.765
Fat flavour	3.54	3.41	0.31	0.835	4.25	3.54	0.34	0.298
Strange flavour	0.72	0.89	0.23	0.711	0.46	1.39	0.29	0.107
Overall	5.44	6.46	0.29	0.078	5.75	5.46	0.24	0.547
SEM = standard error of mean.
*Significance at P<0.05.
**Significance at P<0.01.

With reference to the hardness of the meat, IM obtained lower scores than LM for both carcass weights. Costa et al. (2009) demonstrated that lamb meat derived from extensive production systems is less tender than meat from intensive systems. Similarly, Crouse et al. (1978) and Summers et al. (1978) observed that feeding lambs with a high energetic diet, such as it is used in intensive production systems, increases meat tenderness. Finally, ageing time could have influenced the final meat tenderness, being in agreement with Duckett et al. (1998) who measured an increase of 46% in tenderness as meat was aged 12 days, with the largest increase in tenderness occurring during the first four days. Similar findings have been reported by Jaime et al. (1992).

Finally, IM was juicier than LM; however, significant differences were detected only in samples from 5-kg carcasses. Guignot et al. (1994) described that juiciness is related with meat pH, which increases with the ageing time due to the proteolysis process that decreases with the age of the animal (López and Casp 2003).

With reference to the triangular test, 46.7% of consumers were able to discriminate between LM and IM, which means that almost the half of consumers are able to appreciate the quality difference of both products. A higher preference was found for LM than IM (63.6% vs. 36.4%, respectively) mainly because IM was found to be tenderer than LM, supporting the hypothesis that consumers consider LM as a high quality meat.

4. Conclusion

Several sensorial differences between LM and IM were found in aspects such as lamb smell or hardness by trained panellist. For this reason, this study can be taken as a model to promote LM breeds in order to make them more competitive in markets. However, further studies are needed to analyse carcass and meat quality in order to standardise LM.