Title: Development of standard operating procedures (SOPs) and optimisation of deep-frying methods for enhancing the shelf life and quality of sardines in Lake Victoria, Tanzania

Abstract

Happiness Venant's final project will be published in due time. Until then we share the abstract and a link to a poster.

Sardines (Rastrineobola argentea) from Lake Victoria are a vital source of protein, omega-3 fatty acids, and micronutrients, accounting for approximately 60% of the fish catch in the region. Despite their nutritional value, current small-scale deep-frying practices, primarily conducted by women, lack standardised procedures and data on shelf life and product quality. This study aimed to develop standard operating procedures (SOPs) and optimise deep-frying methods to enhance the shelf life and quality of the product. A mixed-methods approach was used, including semi-structured interviews with 47 women sardine processors in the Ilemela, Nyamagana, and Sengerema districts of Mwanza, Tanzania. A shelf-life experiment was conducted at the Matís Laboratory in Iceland using capelin as a proxy species. Samples were deep-fried in palm oil, packaged in plastic bags and aluminium foil boxes, and stored at 1–4°C, 23°C, and 36°C for 22 days. The analyses included water activity (aw), peroxide value (PV), thiobarbituric acid reactive substances (TBARS), and sensory evaluation. The highest aw (0.6) was recorded on day 22, with storage duration and packaging material having significant effects (P < 0.05). PV peaked at 0.0488 μmol/kg on day 14 and varied significantly (P < 0.05) across packaging types and storage temperatures. The TBARS reached 169 μmol/kg on day 14 in plastic-packaged samples stored at 36°C. Only storage duration significantly influenced the TBARS (P < 0.05). The sensory scores were moderate, with aluminum packaging yielding drier products and reduced fishy flavour. Although the products remained safe for consumption, consumer preferences varied significantly. The study concludes that frying temperature, oil type, packaging, and storage duration are critical for maintaining product quality and shelf life. Further research in Tanzania is recommended to determine the full shelf life of sardines under local conditions.