Abstract:

The acid value is an important indicator to judge the quality of products. This paper reports on the
establishment of a new method for the detection of acid value of laver products. Compared with stirring and sonification,
Soxhlet extraction had higher extraction efficiency while avoiding interferences from oxidation products formed during
the extraction process. Separation of the oil and aqueous phases was achieved by the addition of a proper amount of
neutral saturated NaCl solution to the organic solvent dissolving the oil from laver so that the titration end could be clearly
identified. Based on this, a new method was presented for the detection of acid value of dark and dried seaweed products.
The method was validated by detecting the acid value of different processed laver products by improved volumetric
analysis to obtain RSDs between 0.6% and 7.1%. In conclusion, the new method presented in this study is simple,
accurate and applicable for a wide range of samples.

Key words: laver products, acid value, Soxhlet extraction, volumetric analysis