## 3 Results and Discussion
### Acidity, pH, and SSC  
Over the course of storage, berries' SSC, TA, SSC/TA, and pH changed (Table 2) because of the breakdown of insoluble polysaccharides into soluble sugars and organic acids during respiration and of the water loss [39]. The average tittatable acidity at harvest, expressed as tartaric acid (g/L), ranged between 6.72 and 7.18 for BA and Control samples, respectively. The values were not significantly different at harvest, and during storage, they did not change deeply. Slight variations were observed but without any influence of the factors tested. This is in general agreement with the results of several studies conducted on different grape cultivars, such as _Flame Seedless_[23], which reported the MAP did not affect acidity, even with high %CO\({}_{2}\) (30-40) in the headspace [38]. On the other hand, the tittatable acidity of _Thompson Seedless_ decreased after 30 and 60 days of storage in air at 1 \({}^{\circ}\)C [40]. As  
Figure 3: Bunches of the in-field _A. pullulans_-treated (BA) and untreated (Control) grapes after 30 days of storage in the tested packaging conditions (BD, SP, OP).  
for acidity, the pH of the grapes at harvest was unaffected by the in-field treatment. pH variability is mostly due to the packaging system (\(p\) = 0.000), as it decreased significantly in OP, probably it may due to the water evaporation. The bunches treated with _A. pullulans_ if packaged with BD or sealed (SP) did not experience any significant pH variation, in agreement with other studies that previously reported MAP did not influence pH [41, 42]. The SSC average values of the _A. pullulans_-treated and untreated grapes at harvest were significantly different, respectively, 20.58 and 21.81 \({}^{\circ}\)Brix. The SSC at end storage decreased in all conditions, with different trends. Statistical analysis suggests the treatment and storage period the most influenced SSC (\(p\) = 0.000), while the packaging system used had a weak influence (\(p\) = 0.026). The lowest value reached was observed in those samples packaged with BD, in both BA and Control samples. Concerning the interactions of the variables, treatment\({}^{\circ}\)packaging was quite relevant (\(p\) = 0.014) and the highest SCC values were observed in the BA-OP and Control-SP. The increase of the SSC expected in OP, due to water loss, was observed in BA but did not occur in the Control batch, suggesting that physiological or microbial degradation of sugars may have contributed to the decrease in SSC in that condition. Cold storage coupled with 2%O\({}_{2}\)-5%CO\({}_{2}\) did not affect the SSC in tale grapes [21], but MAP influenced the sugar content upon the headspace mixture used, in particular, high %CO\({}_{2}\) (20-40) were correlated with the lower SSC [5, 38]. Sugar and organic acid content and composition have a major impact on table grape organoleptic quality [43], the sugar to acidity ratio is paramount for the taste of the grape and should not drop by 20 based on the standard table marketing requirements of large-scale retail trade. At harvest, the ratio was higher in Control rather than in BA-treated grapes, and after the cold storage the value dropped in all conditions without falling below 20.