Heat treatment
Heat treatment utilized a submerged-coil heating apparatus following the method of Cole and Jones. Briefly, a stainless steel tube was wound into a 4 inch-dia coli and immersed into a water bath. The coli internal volume was 30 mL. A 20 mL syringe was filled with sample and injected into the coli. The fluid temperature inside the coli was validates to attain the water batch temperature within 1 s by insertion of a thermocouple into the center of the coli. After heat treatment, sample were ejected using forced air into a 20 mL glass vial sitting on ice to stop heat-induced reaction. Samples were heated using hot-fill conditions as used by the beverage industry to prevent yeast and mold growth in shelf stable juices and acidic beverages.