A Study Of Preservation Technique On Coconut Meat Under Low Temperature Storage

For its high content of proteins and fats, fresh coconut meat is easy to perish under the action of microorganisms and enzymes. The variation of coconut meat quality under low-temperature was studied in this paper, and the predominant spoilage organisms were isolated and identified. The inhibition activity and MICs of five kind of preservatives on the predominant spoilage organisms were evaluated. In addition, the suitable heat treatment of coconut meat and combining with preservative were studied. Results as follows:1. Under low-temperature storage, coconut meat begins to perish after4days, sensory of coconut meat gets worse, and the pH value, acid value, peroxide value and total bacteria count increase. After6days, acid value of coconut meat has increased4.67times.2. Five spoilage organisms were screened out by streak plate method and identified by16S rRNA or ITS sequences, L1, L2, L3were found to be Raoultella ornithinolytica, Pantoea ananatis and Enterobacter cloacae respectively, while L4, L5were found to be Pichia sp. and Debaryomyces hansenii respectively.3. Bacteriostasis experiment showed that sodium dehydroacetate showed the strong inhibition activity on all spoilage organisms, even at a low concentration; Among the five kinds of preservatives, the inhibitory effect of tea polyphenols is the worst, and sodium lactate, sodium diacetate, potassium sorbate just can inhibit part of the spoilage organisms.4. All the heat treatments at different temperature or time have preservation effect on the storage of coconut meat, and the treatment of60℃and25min exhibited the highest activity.5. Compared with single treatment, comprehensive treatment could better restrain the spoilage of coconut meat, and the preservation effect of60℃,5g/L sodium dehydroacetate solution treat25min is the best, it can make coconut meat keeping fresh at least25d under low temperature.From the above results, coconut meat is easy to perish even low temperature storage, and the predominant spoilage organisms are Raoultella ornithinolytica, Pantoea ananatis, Enterobacter cloacae, Debaryomyces hansenii and Pichia sp. respectively. The inhibitory effect of sodium dehydroacetate is the best, combining with heat treatment can efficient inhibit the spoilage of coconut meat and the preservation effect of60℃,5g/L sodium dehydroacetate treat25min is the best.