PLEASE LET ME HAVE YOUR COMMENTS ON THE CHANGE OF ACID SO I CAN CONTINUE HELPING YOU OUT. THANK YOU FOR ASKING US.
1- This precipitate appears once you do the blend with other fruits? – No ,she didn’t blend with other fruit. She used Red grape juice conc. only . SO AT WHAT TIME THE PRECIPITATE APPEARS? - It appear the precipitate around 10 days after boiling process 95 degree Celsius, 2 min. I think that 2 minutes at 95 C you might have the chance to degrade other compounds. Is this temperature-time same as the industrial application? – The industrial temp for UHT process around 100-105 C at 30 Sec. INDEED I THINK THAT 2 MINUTES AT 95 C MIGHT PROMOTE SOME PROTEIN DENATURALIZATION AS WELL AS THE COLOR PRECIPITATION, BUT FOR TESTING PURPOSES IN LAB I THINK IT IS JUST FINE.
2- Are you blending as concentrate or as single strength? - She diluted to 15bx. red grape juice before blending. BLENDING WITH WHAT? – Sorry for make you confuse . They only use red grape juice 15 brix , add 0.04 % citric acid and pasteurized for testing process. If you do not add citric acid, this precipitate appears? - In case of don’t add Citric acid , the precipitate don’t appear. Can you recommend any acid can be use instead?. IT IS CLEAR THAT CITRIC ACID TOGETHER WITH PROTEINS DUE TO THE BONDING CAPABILITIES MIGHT PROMOTE A SEDIMENT. PLEASE TRY LACTIC ACID OR PHOSPHORIC ACID OR A COMBINATION OF BOTH. IN THE CASE OF LACTIC ACID, FOR BEVERAGE FORMULATION IT IS VERY GOOD SINCE IT ROUNDS UP THE TASTE. IN FACT IN SPARKLING WINES IT IS NORMALLY EMPLOYED SINCE IT GIVES A ROUND MOUTHFEEL. IN THE CASE OF PHOSHPORIC ACID, GIVES ACIDITY WITHOUT BEING THE FINAL BEVERAGE TOO STRINGENT. PLEASE TRY THIS AND LET ME KNOW.