Sensory, consumer and physico-chemical evaluations of Italian and Spanish long shelf life (LSL) tomato varieties

Long-storage tomato landraces are typically cultivated in non-irrigated fields, and after harvest fruits are stored during a long period of time (up to 6 months, or more). In Italy and Spain, many LSL landraces, including Pomodorino del Piennolo del Vesuvio (Italy), Penjar and Ramellet (Spain), typically tied in bunches and stored hanging, are highly appreciated for traditional culinary uses. In order to better understand the sensory attributes driving consumers' preferences for this typology of tomatoes, in the framework of the TRADITOM project, experiments have been conducted in Spain and Italy including traditional and modern varieties originating from both countries, which have been characterized at three levels: physico-chemical measurements, objective description of sensory properties and consumer preference tests. Due to the specific characteristics of the LSL tomato varieties, and their specific uses in each country, ad hoc protocols were developed for descriptive sensory analysis by trained panels and hedonic tests. Because of the different consumption habits in the two countries (mainly "spread on bread" in Spain, used as "cooked product" in several dishes in Italy), a consensus protocol was limited to descriptors related to appearance and odour evaluation of the raw product. Postharvest behavior of the analyzed genotypes showed a clear adaptation of the local materials to their own environments, since the Italian accessions had a poor shelf life under the environmental conditions used in Spain, and vice versa. Comparisons between Italian and Spanish LSL genotypes showed significant differences for most of the physico-chemical traits measured in both countries, including fruit weight, soluble solids, firmness, and external colour. In Italy, sensory and hedonic evaluations were conducted at 4.5 months after harvest, which falls within the representative period of greater sales for the Pomodorino del Piennolo. The results showed that traditional varieties had better scores for 'odour' and texture ('cut-resistance') descriptors, and were lower in 'seeds' and 'bitterness' than the commercial counterpart. In terms of consumer appreciation, better preferences were detected for some traditional varieties, when evaluated uncooked because of their best 'firmness' and intense 'odour'. In Spain, no clear differences where found between modern and traditional genotypes evaluated by the trained panel after 3 months postharvest, although for specific traits traditional varieties scored better than their modern counterparts (e.g. 'overall tomato flavour', 'shrivelling' or 'number of seeds on bread'). In a second experiment, recently harvested fruits were compared with 3 months aged fruits, revealing that storage caused a reduction in the intensity of perception of the sensory attributes, but that cooking properties ('spreadability') and specific sensory profiles (e.g. 'green odour') emerged during postharvest. Hedonic tests revealed that liking was highly related to CATA (Check-All-That-Apply) descriptors 'pronounced tomato aroma' and 'sweet on bread', signaling that both are key attributes driving consumer preferences. On the other hand, liking was negatively correlated with 'too much acid on bread', 'unpleasant after-taste on bread', 'too many seeds', and 'it is difficult to spread'. Results presented here are of special interest for the valorization of these LSL tomato varieties.