2.4. Haze dextran in sugarcane syrups
Haze dextran in sugarcane juices was based on ICUMSA GS1–15 [1994] and rapid haze [16] methods with modifications to improve the accuracy and precision. Juice (35 ml) was pipetted into a conical flask and termamyl
TM
(Novo, US) amylase (0.1 ml) added at 55 8 C for 15 min to degrade starch. The mixture (10 ml) was then pipetted into a 25-ml plastic syringe with a filter holder attached, containing a coarse glass filter (25 mm). TCA (10%) solution (2 ml) was then pipetted into the syringe body and 0.5 g high-grade celite filter aid (Aldrich, US). The plunger was placed in the syringe, and inverted at least five times. The first 2 ml of filtrate was discarded, and then 5 ml filtrate was added to 5 ml absolute ethanol, mixed and left for 2 min. The absorbance at 720 nm was immediately read in a 1-cm cell on a Shimadzu UV–vis-1201 spectrophotometer. The amount of dextran was calculated using the same standard curve as for the ICUMSA haze dextran method above.