The partition coefficients (K ow) of benzoic acid and sorbic acid in systems of fish oil (sand eel)-water, fish oil-buffer solution, rape oil-water and olive oil-water were experimentally determined in a temperature range from 5 to 43°C and pH from 4.5 to 6.5°C. The dimerization of benzoic acid in fish oil-water system was observed at 25°C. Two modifications have been made to the Nordic Food Analysis Standard for the determination of sorbic acid by HPLC. The experimental results show that the K ow of benzoic acid and sorbic acid in fish oil-buffer system is ca. 100 times lower than that in fish oil-water system. The K ow values of benzoic acid and sorbic acid in fish oil and water system decrease with increasing system pH values. The partition coefficients of plant origin and fish origin oils are in the same order of magnitude even though their molecular structures are very different.

There is growing demand for functional food products enriched with long chain omega-3 polyunsaturated fatty acids (LCω3PUFA). Nanoemulsions, systems with extremely small droplet sizes have been shown to increase LCω3PUFA bioavailability. However, nanoemulsion creation and processing methods may impact on the oxidative stability of these systems. The present systematic review collates information from studies that evaluated the oxidative stability of LCω3PUFA nanoemulsions suitable for use in functional foods. The systematic search identified seventeen articles published during the last 10 years. Researchers used a range of surfactants and antioxidants to create systems which were evaluated from 7 to 100 days of storage. Nanoemulsions were created using synthetic and natural emulsifiers, with natural sources offering equivalent or increased oxidative stability compared to synthetic sources, which is useful as consumers are demanding natural, cleaner label food products. Equivalent vegetarian sources of LCω3PUFA found in fish oils such as algal oils are promising as they provide direct sources without the need for conversion in the human metabolic pathway. Quillaja saponin is a promising natural emulsifier that can produce nanoemulsion systems with equivalent/increased oxidative stability in comparison to other emulsifiers. Further studies to evaluate the oxidative stability of quillaja saponin nanoemulsions combined with algal sources of LCω3PUFA are warranted.

The suitability of a number of 'off-the-shelf' food items for use as secondary reference materials for incorporation into routine work batches to enhance quality assurance has been evaluated over a 5 month period. The commodities were canned ham (tested for cholesterol and fatty acids), wheat germ (tested for fatty acids, thiamine, riboflavin and niacin), two fish oils (tested for fatty acids) and powdered orange drink vitamin C supplement (tested for ascorbic acid). Foods were purchased locally and analysed using recognized methods. Seven replicate analyses were performed initially on each food to establish homogeneity, with subsequent analyses in triplicate. Overall mean results (+/-2 s.d.) for the 5 month study were as follows: cholesterol in canned ham, 65 +/- 7.2 mg/100 g; thiamine in wheatgerm, 1.97 +/- 0.26 mg/100 g; riboflavin in wheatgerm, 0.27 +/- 0.17 mg/100 g; niacin in wheatgerm, 7.1 +/- 0.9 mg/100 g; ascorbic acid in vitamin C supplement, 718 +/- 70 mg/100 g; C18:0, C18:1 and C18:2 in wheatgerm, 0.72 +/- 0.11, 15.2 +/- 0.5 and 57.7 +/- 1.4% total fatty acids respectively; C18:0, C18:1 and C18:3 in canned ham, 12.5 +/- 0.6, 44.7 +/- 1.4 and 0.57 +/- 0.12% total fatty acids respectively; C18:0, C20:5 and C22:6 in cod liver oil, 2.4 +/- 0.1, 12.6 +/- 1.2, and 5.6 +/- 0.8% total fatty acids respectively; C18:0, C20:5 and C22:6 in omega 3 fish oil, 3.7 +/- 0.2, 19.2 +/- 0.5, and 12.8 +/- 1.4% total fatty acids, respectively. Statistical data were obtained from the multiple analyses, and based on the data generated, the foods tested were shown to have satisfactory homogeneity and stability for use as secondary reference materials over an extended period.