Discrimination of defective dry-cured Iberian ham determining volatile compounds by non-destructive sampling and gas chromatography

Abstract

Evaluation of dry-cured Iberian ham quality is carried out by means of the sense of smell of experts and a percentage of these hams are discarded due to odour defects. However, hams in cellars cannot be altered by sampling because they would be devaluated, which makes instrumental analysis difficult. Thus, the aim of this work is to assess the potential of headspace gas chromatography coupled to ion mobility spectrometry (HS-GC-IMS) or mass spectrometry (HS-GC-MS) to discriminate defective Iberian hams using a non-destructive sampling. Fifty hams from pigs fed with acorns were sampled in a real industry setting and were classified according to their condition (defective or non-defective). Validated classification rates of 80% and 100% using partial least squares discriminant analysis were obtained with HS-GC-IMS and HS-GC-MS, respectively, demonstrating the potential of the instrumental methods tested, which can be seen as complementary to the traditional olfactory technique. Furthermore, the volatile profile of spoiled Iberian hams was also determined; on average, spoiled pieces showed higher values of nonanal and decanal. Besides that, formic acid was only detected in spoiled pieces. These results might lead to an easier discrimination of spoilage to guarantee the quality of Iberian hams on the market.