2.6. Sugars, acidity, ascorbic acid and alcohol insoluble residue (AIR)Thirty grams of ground celery was extracted with 100 mL of ethanol. After centrifugation the supernatant was used to evaluate soluble sugars with the anthrone reagent (Leyva et al., 2008). Results were expressed as g kg−1. Acidity, was evaluated on 10 g samplescelery according to AOAC (1980). Results were expressed as [H+] mmol kg−1. Ascorbic acid (AA) was evaluated by HPLC according to Wimalasiri and Wills (1983). Results were expressed as μmol kg−1. Cell wall isolation was carried out as Vicente et al. (2007).2.7. Sensory evaluationPetioles stored for 6 days at 4 °C were randomly coded and served at 18–20 °C to 90 non-trained panelists who scored the samples from 1 (poor) to 9 (excellent) for the attributes aroma, freshness, color and overall acceptability.2.8. Microbiological counts