Effect of processing treatments on the organoleptic and physicochemical quality of shallot puree upon storage

H.A. Hasimah, O. Normah and M.Y. Rafiah Hasanah

Abstract

The effects of processing treatments on the organoleptic and physicochemical quality of shallot puree and the possibility of extending its storage life by acidification, heating and chilling methods were studied. Shallot (Allium cepa L.) puree were prepared and subjected to four treatments viz. (a) acidification with citric acid to pH 4.4 and chilled (AC), (b) heated to 60 °C and chilled (HC), (c) acidification with citric acid to pH 4.4, heated to 60 °C and chilled (AHC), and (d) chilled (C). Samples were evaluated at 2-week intervals together with freshly prepared samples. Sensory, pH, total titratable acidity, colour and total volatile oil evaluations were conducted. The AHC treatment allowed shallot puree in aluminium laminate packaging to be kept for 8 weeks. This treatment was better than either acidification or heating alone (under chilled storage), and produced ready-to-use products that were acceptable for cooking. In terms of colour attractiveness, AHC, AC, HC and C treatments gave attractive colour in descending order. Under chilled storage, heating improved colour of samples but acidification was better than heating. Acidification together with heating followed by chilled storage in aluminium laminate bags produced shallot puree with better and comparable colour to fresh shallot puree, up to a shelf life of 8 weeks.

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