**3. Discussion**

Only fresh produce that meets the consumer's standards is suitable at the market interface. As a result, evaluating the impact of possible novel procedures on the sensory and organoleptic features of fruits and vegetables is critical. Weight loss, color, firmness, total soluble solids, total acidity, and antioxidants are only a few attributes that affect postharvest fruit quality. Moreover, the postharvest performance of the tomato ripening stage and understanding the physiological changes taken place during storage are of high research interest [37]. In the present study, mature green tomato fruit when were subjected to EO-enrichment (sustained effect) were perceptibly retained their firmness in low EO levels (50 μL L<sup>−</sup>1). However, the rates of respiration and ethylene as well as the antioxidant metabolism were increased in high EO levels of 500 μL L−1, and the effects were more

pronounced during the storage period of 14 days, in comparison to the control fruits (subjected to typical storage and transportation methods). When red tomatoes (being in higher maturation stage compared to mature green fruit) were subjected to EOs, effects on quality attributes were appeared even earlier, after two days of EOs exposure, with increase of TSS, and *β*-carotene and decrease on lycopene content. Considering the preexposed fruits to EOs, quality attributes were more affected in mature green fruits and to a lesser level in the red fruits. Furthermore, based on appearance, color, and texture evaluations, taste panel trials demonstrated an overwhelming preference for EO-treated red fruits during choice testing.

The relationship between increased ethylene production and tomato ripening is well understood [33] and effects are related to the fruit ripening stage, by altering signaling genes related to ethylene metabolic pathway [37]. In addition to the ripening stage, biotic and abiotic stresses have an impact on ethylene production [38]. In tomato fruit, the increase in respiration occurs either concurrently or shortly after the increase in ethylene production [39,40] and this was evidenced in both mature-green and red tomatoes, starting from the 2nd day up to 14th day of storage for the high EO concentration of 500 μL L−1. Interestingly, mature green tomatoes stimulated more the respiration rates compared to the relevant red tomatoes with the EO of 500 μL L<sup>−</sup>1. When ethylene is added to mature-green tomato fruit, ethylene hastens the climacteric and ripening process [37], meaning induced respiratory climacteric due to increased endogenous ethylene output in tomato [41]. That could be the case in our study, but further research is needed to that direction before final conclusions. As a result, a comprehensive investigation at the molecular level is required to investigate the effects of EOs on gene and/or protein expression in metabolic pathways, such as the ethylene biosynthesis pathway, which is linked to fruit ripening (particularly in climacteric fruits such as tomatoes).

Fresh commodities loss weight mainly by vapor pressure at different locations [42] but also through the respiration process [43]. A loss of more than 5%, on the other hand, is a limiting factor for the fruit marketing and consumption [44]. However, weight loss in the present study was <1.8%. Fruit treated with EO lost less weight during storage than fruit that had not been treated with EOs, and weight loss increased progressively over time. This decrease in weight loss could be attributed to the ability of the EOs to decrease water exchange and solute movement due to EOs hydrophobic properties [45]. The ability of the essential oil to act as a barrier and the antioxidant activity of the essential oil coatings were responsible for the reduced weight loss rate in coated fruits during storage [46,47].

During fruit maturation and storage time, titratable acidity is decreased and TSS is increased in general, as this trend was observed in our study. TA was decreased up to 17% from day 0 to day 14, and the values were ranged from 0.2 to 0.6%, being in agreement with previous records [40].

EO application as preservative means is well documented due to their antimicrobial and antioxidant activities [12,13,48,49]. Moreover, sage (*Salvia officinalis* L.) antibacterial and antifungal properties have been reported previously [50]. In the present study, sage EO maintained their antimicrobial efficiency up to 14 days, with reduced decay symptoms, being in accordance with previous applications of cinnamon and eucalyptus EO on tomatoes and strawberries [22]. In the present study, the main component of sage EO was eucalyptol, as described at the Section 4, with proven antimicrobial activity [51,52]. Additionally, secondary components of sage EO, such as camphor and *α*-pinene have also antimicrobial activity [53,54]. Both primary and secondary components of an EO contribute to the antimicrobial activity of the oil, affecting the quality of the fresh produce. Fruit decay causes metabolic alterations that are responsible for unpleasant smell and flavor [40]. Based on the findings of this study, it is hypothesized that the active component in sage EO continues to be released throughout storage, extending the fruit's shelf-life. Additionally, the effects were persisted even when fruits removed from the EO and were stored in ambient air for seven days, indicating a residual effect. Similarly, sage EO revealed residual effects in pepper fruits [36].

The pigment content of the fruit changes during development, whereas the chlorophyll level falls during ripening, prompting the synthesis of carotenoids, including the red pigment lycopene as well as *β*-carotene. In red tomatoes 500 μL L−<sup>1</sup> EO-treated fruits had lighter (higher *L\** value) color than the untreated ones during two and seven days of storage at 11 ◦C, suggesting delayed color development by EO treatment [55]. This was evidenced by the decreased lycopene levels for the EO-treated fruits up to seven days of storage. However, this effect did not persist after 14 days of storage. Noticeably, delay in color development was evidenced in pre-exposed mature-green tomatoes to 500 μL L−<sup>1</sup> EO-treated after seven days of EO exposure and additional seven days of storage in clean air (as "7 + 7 days" treatment).

The mechanisms underlying the effects of EOs on fruit firmness are unknown. However, it is known that during fruit ripening, cell wall matrices, particularly pectins, are disrupted, and these modifications are thought to be responsible for the decrease in tissue firmness that occurs with ripening [56,57]. In the present study, fruit firmness was maintained in tomatoes-enriched with 50 μL L−<sup>1</sup> EOs for up to 14 days, compared with higher concentration (500 μL L<sup>−</sup>1) in both red and breaker fruits. The effect of EO was even persisted in fruits pre-exposed to EO (50 μL L−1) and stored for an additional seven days in ambient air.

Depending on the species, cultivar, temperature, and climatic and environmental conditions during the growing period, the evolution of total phenolics in fruit during storage could be different [58]. The key contributors to the soluble antioxidant activity in tomato fruit, ascorbic acid, and soluble phenolics increased with storage, resulting in an increase in antioxidant activity in tomato fruit [59]. According to one study, ascorbic acid comprises 28–38% of soluble antioxidant activity, with soluble phenolics accounting for the rest [60]. In our study, increased AA levels were found at two days of EO-treated fruits reflecting the increased DPPH levels found at two and seven days in red tomatoes and at seven days in breaker fruits. Antioxidants help to avoid the build-up of potentially harmful reactive oxygen species (ROS), which are produced as a by-product of cellular metabolism and serve as secondary messengers in hormone signaling [61]. Since tomato fruit is known to be particularly rich in antioxidants [62], such as vitamin C, carotenoids (especially lycopene; [62]), and vitamin A, the antioxidative characteristics of tomato fruit and tomato products are affected by storage procedures, which is a source of worry [63]. Indeed, tomato fruit is an essential nutritional source of several of these compounds, which are vital in the prevention of chronic diseases including heart disease and cancer [64]. The temporary rise in AA content in breaker and red tomatoes (including *β*-carotene in red tomatoes) after two days of EO-enriched atmosphere is noteworthy in this regard. Moreover, EO of 50 μL L−<sup>1</sup> in red tomatoes kept MDA levels down indicating less stress on the fruits.

During choice testing, panel trials demonstrated a clear preference for EO of 50 μL L−<sup>1</sup> treated fruits in red tomatoes compared to the untreated fruits, while the opposite was evidenced in breaker tomatoes. Appearance and texture were the main indicators for breaker fruits, while for red tomatoes, not only appearance and texture but also color, aroma, and sweetness were scored to similar levels in low EO-treated fruits and in the control.
