Changes in Ripening-Related Quality Traits of Long Shelf Life Tomatoes as Influenced by Water Deficit and Short-Term Postharvest Storage

Abstract

The diversity preserved within the European long shelf life tomato landraces (LSL) is a unique source to design high quality tomato products better adapted to changing environmental conditions and, thereby, to reduce food losses. The adaptation of LSL to water deficit (WD) management practices and their postharvest keeping ability can be used as tools to concomitantly enhance fruit quality and sustainable production. In this study, we investigated the effect of WD conditions and the plant growing environment (open field vs. tunnel) on quality traits of two genotypes of the Penjar LSL variety (modern hybrid (MV) and landrace (LR)). Changes in ripening-related quality traits (fruit ethylene production, respiration rate, firmness, color, soluble solids content, titratable acidity and the content of antioxidants, as well as specific sugars and acids) in response to the different preharvest factors were evaluated at the time of harvest and after a short period of storage (30 days), following actual commercial practices. Significant differences among genotypes were encountered for most quality traits at the time of harvest and higher intra- and inter-environment heterogeneity was observed in the LR than in the MV genotype. In general, Penjar tomatoes exhibit a low physiological activity (ethylene production, 0.56–1.33 µL kg−1 h−1, respiration rate: 0.015–0.026 mg CO2 kg−1 h−1) at harvest. In both genotypes, WD increased to a different extent the fruit external color (redness, lightness) as well as the sensory (SSC) and nutritional (antioxidant capacity) fruit profiles. By contrast, the growing environment had little impact on most fruit quality traits. Postharvest storage only led to a slight reduction in the fruit respiration and ethylene production, lower sugars and acids content, enhanced color and no firmness changes. Overall, the results from this study demonstrate that selecting the appropriate genotypes is the most important step towards the design of high-quality LSL tomatoes, while WD and short-term storage can be used by farmers as a strategy to differentiate the product quality in specific market niches.

Local Agro-Environmental Conditions Impact Fruit Quality, Sensory Properties and Consumer Acceptance of Long Shelf-Life Tomatoes

“…Our results have shown that the agro-environmental conditions traditionally adopted for the 'Piennolo' variety, which also include a "seccagna" (lack of irrigation) cultivation method, significantly increased SSC and redness while reducing FW and FIRM in both the 'Penjar-Ramellet' and 'Piennolo' groups. These effects of water deficit on fruit quality traits have been widely reported in the literature for the LSL tomato group [36,[54][55][56] and are similar to those described for tomatoes in general [24]. Taken together, our data show that the 'Piennolo' and 'Penjar-Ramellet' accessions analyzed in this study lost their peculiar phenotype when not cultivated in their original agro-environmental conditions.…”

“…Regarding the evolution of fruit color during the postharvest period, the 'Piennolo' (grown in Italy) and 'Penjar-Ramellet' (grown in Spain) groups showed a different pattern, the most important being the increase and the decrease in redness for the 'Penjar-Ramellet' and the 'Piennolo' groups, respectively. Moreover, a reduction in SSC, FIRM and FW was observed during postharvest in the 'Piennolo' group; this trend was also previously described in 'Penjar' landraces [36,41].…”

“…The sensory ideotypes of the different tomato horticultural groups, fresh-market (cherry, salad) and processing, have been widely discussed in the literature [24,25,[29][30][31][32]; nevertheless, few reports can be found for the long shelf-life (LSL) landraces cultivated in Southern Italy and Eastern Spain. LSL varieties can be defined as a differentiated tomato group [1,33] characterized by an extended fruit shelf-life, which can exceed 5 months (non-LSL tomatoes showing an average shelf-life of 1-2 weeks), under not controlled storing conditions; a small fruit size (<80 g) with a high agro-morphological diversity across accessions; and an abnormal ripening and postharvest behavior [34][35][36][37]. European LSL varieties can be classified into two main groups according to their geographic origin: the Italian group, generically referred to as 'da Serbo' landraces, and the Spanish group, including the 'Penjar' and the 'Ramellet' landraces [1,38].…”

“…This sensory diversity is probably linked to the multiplicity of preferences and uses that these traditional varieties have across the Mediterranean basin [33]. In addition to the diversity at harvest, LSL fruits usually go through an 'aging' period (at least 1-2 months of storage) before they are consumed, which alters the composition of the fruit [16,36,[41][42][43]. Thus, the sensory characteristics of the LSL fruits evolve during the postharvest stage, resulting in a sensory profile marked by organoleptic attributes not perceptible in fresh tomatoes at harvest.…”

Marker assisted backcrossing of alcobaca gene into two elite tomato breeding lines

“…The occurrence of PG enzyme strongly associates with the onset of cell wall degradation. The natural synthesis of ethylene starts before the synthesis of PG enzyme and the exogenous ethylene that facilitate the accumulation of the enzyme in mature fruits (Grierson and Kader, 1986;Casals et al, 2021). The crop is characterized by remarkable post-harvest losses generally due to its high perishability and the poor storage conditions under which fruits are kept.…”