Effect of Treatment and Refrigeration on the Chemical and Microbiological Stability of Avocado (Persea Americana) Spread

Abstract

Avocado pear (Persea americana) was pulbed, blanched, mashed and treated with 3.3% salt, (sample B), a combination of salt and 7:5% lime juice (sample C) and a control (Plain), as sample A. All three samples were stored under refrigeration temperature (4°C) for a period of four days. Sensory evaluation conducted with sliced bread and biscuits showed that the spread treated with salt (Sample B) was preferred in terms of colour, texture, flavour and overall acceptability. All samples stored and evaluated daily showed sample A with a free fatty acid range of 1.65% - 1.95% while sample B had a decreased free fatty acid from 1.53% on day 0 to 1.41% by the fourth day of storage, although, the difference between treatments were not significant (P>0.05) a minimal decomposition of fatty acid was observed. A significant reduction was observed in the peroxide formation in sample C with peroxide values ranging from 0.33 meg/kg on day 0 to 0.19 meg/kg by the fourth day. Other samples, A and B showed a gradual increase in peroxide formation during storage. Microbial count (cfu/g) was higher in sample A (control) with highest count of 8 x l0⁷cfu/g observed in day 2. Samples treated with salt and lime juice (sample C) was more effective in the control of microorganisms with counts between 9 x l0⁴ cfu/g, and 3 x 10⁵ cfu/g for days 0 and 4 respectively.