Micro-structural and quality changes in growing dark-purple eggplant (solanum melongena L.) as affected by the harvest season

VALERGA, LUCÍA; DARRÉ, MAGALÍ; ZARO, MARÍA JOSÉ; ARAMBARRI, ANA; VICENTE, ARIEL ROBERTO; LEMOINE, MARÍA LAURA; CONCELLÓN, ANALÍA

SCIENTIA HORTICULTURAE

ELSEVIER SCIENCE BV

Año: 2019 vol. 244 p. 22 - 30

0304-4238

Whereas the production season is accepted to exert profound influence on fruit physiology, micro-structure andquality, very few studies have attempted to find liaisons between these traits. Herein, we determined the microstructuraland quality changes of eggplant fruit produced in Late Spring (mean air temperature 22 °C; max. 28 °C;min. 16 °C), Late Summer (mean air temperature 19 °C; max. 25 °C; min. 13 °C) and Late Fall (mean air temperature11 °C; max. 15 °C; min. 6 °C), at three growing stages: Baby (S1, 9 cm length), Commercially mature (S2,17 cm length) and Advanced commercially mature (S3, 21 cm length). We followed fruit elongation and assessed atharvest the size of epidermal and parenchyma cells, cuticle thickness, respiration rate, dry matter, firmness, seednumber, seed size and seediness. The time required to reach commercial maturity was 3?4 times shorter in LateSpring than in Late Fall. Micro-structural evaluations showed that Late Spring fruit had epidermal and epicarpcells per unit area than Late Fall eggplants, which in turn presented thinner cuticles and a less compact largecelledcentral endocarp parenchyma. Commercially mature Late Fall eggplants also lighter color, showed lowerrespiration and were firmer than fruit growing earlier in the season. For all maturity stages fruit dry mattercontent was the parameter correlating best with fruit firmness (r = 0.71). Late Summer fruit tended to showintermediate properties, but had higher seed number, size and seediness. Overall, results show the influence thatthe growing season exerts on eggplant metabolism, micro-structure and quality