**Author details**

twice higher AI (up to 0.94) and higher TI (up to 0.37) values, but significantly lower h/H levels (up to 1.92) in comparison with our results. Moreover, the authors report different seasonal changes in FA distribution, especially between individual SFA and PUFA. The possible reasons for the observed discrepancies are different mussel populations (subtidal mussels)

The hypercholesterolaemic-atherogenic potential of mussel lipids is related to their cholesterol content and FA profile. In the present chapter, cholesterol/SFA index (CSI) and cholesterol index (CI) were determined for the assessment of this potential. CSI was used to compare different types of food, whereas CI predicted the possible variation in an average individual serum cholesterol, which could be affected by individual portions of food. Seasonal variation was found for CSI (3.85–4.79) and CI (3.7–4.06). The calculated CSI and CI values are comparable with those calculated for red and pink shrimps from the Ionian Sea [50]. The low values of both indices found for the Black Sea mussel lipids indicated their high functional properties

The amount of fat-soluble vitamins provided by 100 g raw mussel tissue was calculated as a percentage of the average daily allowance (ADA) and was compared with the RDI, accepted in Bulgaria [42]. Bulgarian dietary standards for ADA are close to those accepted in the European Union [52] with the exception of the RDI for vitamin D3 (5 μg for adults in our country, while the recommendation of the European Union is 10 μg). According to the Dietary Standards in Bulgaria, the analyzed mussels could supply a low percentage of RDI of vitamin A (4.9–6.7%) and of vitamin E (13.2–15.4%). Substantial amounts of vitamin D3 were found in farmed mussels, where 100 g raw mussel tissue could provide between 50 and 62% of the average daily intake. Minor seasonal changes were found for the recommended daily intake values of vitamins A and E, whereas a more significant fluctuation was observed for vitamin D3. The highest RDI levels for all three fat-soluble vitamins were found in the summer season. An earlier investigation of farmed and wild mussels from Bulgaria [36] presents similar low amounts of aquaculture mussel vitamin A and E levels of RDI and lower values of

The relationship between vitamin E and PUFA intake (for adults), presented as >0.5 for mg vitamin E/g total PUFA ratio, could also be used as a criterion for evaluation of the functional qualities of the mussel lipids (see **Table 4**). This ratio is based on the minimum requirement for vitamin E content, allowing for cellular synthesis and PUFA cellular membrane retention; and vitamin E amounts, required to protect and metabolize dietary PUFA [53, 54]. Based on the calculated ratio, which ranged between 1.6 (autumn) to 3.57 (summer), we can conclude that mussel lipids contained compounds with high biological activity and well-balanced Vit

The study investigated seasonal changes in the quantities of macro-components and fatsoluble biologically active compounds in the edible tissue of the aquaculture mussels from

and protective role against the risk of cardiovascular disease [51].

vitamin D3 RDI in comparison with the present study.

E/PUFA ratio.

**4. Conclusion**

and locations, available food, sex, etc.

194 Biological Resources of Water

Albena Merdzhanova\*, Diana A. Dobreva and Veselina Panayotova

\*Address all correspondence to: a.merdzhanova@gmail.com

Department of Chemistry, Faculty of Pharmacy, Medical University, Varna, Bulgaria
