Effects of ascorbic acid, sodium metabisulfite and sodium chloride on freshness retention and microbial growth during the storage of Manzanilla-Aloreña cracked table olives

The effect of the mixture of sodium metabisulfite (SM), ascorbic acid (AA), and NaCl on the surface colour of fruits and microbial growth during the storage of cracked Manzanilla-Aloreña table olives was studied. During storage, the green colour of fruits, measured by the hue angle (tang−1(b/a)), decreased rapidly, indicating a degradation in the green and a change towards more reddish tones. The degreening rate (kc) was lower for the highest AA concentration, while the highest final hue angle was found for the highest SM level, indicating different antioxidant mechanisms. Enterobacteriaceae were not enumerated after 20 days of brining. AA, SM, and NaCl, within the concentrations essayed, did not affect yeast growth; however, lactic acid bacteria (LAB) were partially inhibited by the presence of SM and AA, showing the highest growth rate in the absence of both. The maximum population of LAB was reached at levels of SM below 0.75 g/l, intermediate AA (7.5 g/l) and NaCl (70 g/l) concentrations. Appropriate storage conditions could be obtained at the maximum levels of AA (15.0 g/l) and SM (1.5 g/l) and the lowest level of NaCl (60 g/l).