Shelf life definition for Italian anchovies inoculated with Lactobacillus plantarum and Bifidobacterium animalis subsp. lactis

Abstract

This paper reports on the optimization of marinated anchovies, inoculated with two probiotic strains ( Lactobacillus plantarum and Bidifobacterium animalis subsp. lactis ). The research was divided into three phases: a) choice of the hurdles for the marinating brine; b) brine optimization; and c) production of functional anchovies. After studying the effects of pH and NaCl as typical hurdles of brine, the effect of citrus extract towards the probiotics was assessed; this antimicrobial agent was chosen as an additional hurdle for product storage. Process optimization, conducted through the use of a centroid design, revealed that the optimal composition for marinating brine was the following: 2% of acetic acid, 10% of NaCl and 200 ppm of citrus extract. Then, anchovies were inoculated with probiotics, marinated, packed under different conditions (air, vacuum, in oil and in a diluted brine) and stored at 4 °C. During 21 days, analyses were performed to evaluate quality attributes (odor, color, texture and overall quality) as well as the survival of the tested strains. The limiting factors for shelf life definition resulted to be sensory scores (odor in particular); the best sample was that packed in diluted brine, as it retained the sensory quality at the maximum level for at least 6–10 days and showed a shelf life longer than 21 days. This paper proposes a new kind of functional food, based on marinated anchovies. The new non-dairy functional food may both contribute to a regular assumption of probiotics in individuals with lactose intolerance or with a diet lacking milk-derived products and to expand the range of health-promoting foods. By increasing the amount of functional foods in the diet, will be easier for consumers to achieve the optimal supply of probiotics able to guarantee a healthy bacterial gut flora. Moreover, anchovy is a low cost product in Southern Italy; therefore the preparation of a functional dish with this kind of raw material could be a promising way for small-scale producers and very attractive for consumers, due to mild treatments used for its stabilization. ► Fish is a suitable carrier for probiotics. ► Lactobacillus plantarum is resistant to marination process. ► The shelf life of anchovies inoculated with probiotics is at least 21 days. ► Marinated anchovies with probiotics could broaden the range of functional foods.