Page 67 - Analytical method for food addtives

6

E200–3: Sorbic acid and its salts

6.1 Introduction
Sorbic acid is used as a preservative in a wide variety of foods. Sorbic acid retards
the growth of yeast and moulds and is usually added to foods as a salt. The major
food groups contributing to dietary intake of sorbic acid constitute a wide variety
permitted at the following levels: various foods 200–2000 mg/kg (liquid egg
5000 mg/kg, cooked seafood 6000 mg/kg) and soft drinks, wine etc. 200–300 mg/
kg (Sacramental grape juice 2000 mg/kg, liquid tea concentrates 600 mg/kg). The
acceptable daily intake (ADI) for sorbic acid is 25 mg/kg body weight.

6.2 Methods of analysis
There are numerous methods published for the determination of sorbic acid in
foodstuffs. The majority of these methods are separation methods. Methods that
have been developed for sorbic acid in foodstuffs include gas chromatography
1–7
(GC), high pressure liquid chromatography (HPLC), 8–14 spectrophotometric, 15–21
22
high performance thin layer chromatography (HPTLC) and micellar electrokinetic
23
chromatography (MECC). A summary of these methods is given in Table 6.1,
together with the matrices for which the methods are applicable. If statistical
parameters for these methods were available these have been summarised in Table
6.2. Three of these methods 1,15,16 are AOAC Official Methods of Analysis and one 1
has been collaboratively tested.
1
The NMKL-AOAC method was collaboratively tested on apple juice, almond
paste and fish homogenate [at 0.5–2 g/kg levels], representing carbohydrate-rich,
pasty, rich in fat and carbohydrates, and protein-rich foods. In this method sorbic
acid is isolated from food by extraction with ether and successive partitioning into