Effects of a Harvesting and Conservation Method for Small Producers on the Quality of the Produced Olive Oil

Abstract

The production of ‘Premium’ olive oil depends in large part on the quality of the fruit. Small producers see themselves confronted with vast investments and logistic snags when they intend to optimize the harvesting. Today, manual harvesting devices promise less damaged fruit when compared to the traditional methods with nets while the use of a cooling room on the farm is suggested as a solution when the harvesting needs to be stretched out over several days. The use of a manual inverted umbrella during the harvest, together with a storage of up to 14 days at 5 °C, was studied for three cultivars (‘Arbequina’, ‘Picual’, and ‘Verdial’). Ten parameters of the produced oil were examined in two consecutive years together with an extended sensory analysis in the first year. The results underline the importance of the used harvesting and conservation method on the quality of the extracted oil, although the effect size of each factor varied in time and according to the cultivar. The results indicate that small producers with financial and logistic restrictions can obtain a high-quality product following the actions shown in this work, being able to compete in terms of quality in the market, either by combining both methods or by choosing the one that guarantees the best results given the cultivar and the specific storage time they need to consider.

Cold Storage and Temperature Management of Olive Fruit: The Impact on Fruit Physiology and Olive Oil Quality—A Review

“…Significant differences between the 'Manzanilla de Sevilla' and the 'Manzanilla Cacereña' were observed in a similar study [43]. Differences on both the fruit as well as oil characteristics of the cultivars studied were confirmed between the Italian varieties 'Carolea' and 'Ottobratica' [34] and the 'Arbequina', 'Picual' and 'Verdial' cultivars [45,46].…”

“…In line with the observations of Maxie, storage at 0 • C was neither recommended because of the risk of chilling injuries [3]. In the following decades, the potential to cold storage olive fruit was evaluated and confirmed by Californian [26,28], Australian [29]; Israelian [30], Italian [31][32][33][34][35], Spanish [36][37][38][39][40][41][42][43][44][45][46], Portuguese [47], Egyptian [48], Tunisian [49][50][51][52][53][54], Turkish [55], Iranian [56,57] and Croatian [58] research centers, which used most of the time the local cultivars for their experiments.…”

“…Keeping harvested olives at 5 • C for a short time, offered a solution to preserve the quality of the fruit until the necessary quantity for transport to the mill was reached. Combined with a gentle harvesting method, the refrigeration method made it possible to extract high-quality oil without disproportionate investments [45,46]. Cooling the fruit at the farm for a short term opens up new possibilities to revalorize the advantages of cold storage.…”

“…The effect of the storage time on the quality parameters, and especially on the FFA, is profoundly studied and confirmed for a wide range of varieties. fruit quality and deficient oils, the maximum storage time was reduced and the observations were made within shorter intervals [29][30][31]45,46,49,[51][52][53]70]. Monitoring the amount of polyphenolic and volatile compounds in the stored oils, triggered even more precise observations for only several weeks and between days [34,[40][41][42]58].…”

“…'Manzanillo' olives stored under different temperatures and levels of 5% of CO2 caused internal injuries, while storage at 2% O2 retarded fruit When in the 1990's the interest in cooling olive fruit took form, timespans up to 3 months were used to follow the official quality parameters of the olive oil [10,17,27,68,69]. Once it became clear that cold storage for more than one month resulted in problematic fruit quality and deficient oils, the maximum storage time was reduced and the observations were made within shorter intervals [29][30][31]45,46,49,[51][52][53]70]. Monitoring the amount of polyphenolic and volatile compounds in the stored oils, triggered even more precise observations for only several weeks and between days [34,[40][41][42]58].…”