Kajian perubahan flavour buah durian terolah minimal berlapis edibel selama penyimpanan

Abstract

Durian is called king of fruit, because of the delicious taste, and has large consumers. At present, consumers have less time to prepare their meals at home as a result of more time used for their job outside home. So, there is a chance to expand minimally processed fruits to enter food markets. Because of lossing of their peel, minimally processed fruits are more perishable. An alternative to reduce the quality degradation rate and to prolong storage life of minimally processed fruits is by applying an edible coating film. Edible coating film can reduce oxygen and carbon dioxide diffusion, water vapor transmission rate, and flavor transmission. An experiment was conducted with the following objectives : 1) to obtain the suitable formulae of edible coating that was applicable for minimally processed durian; 2) to obtain edible coating formulae that has low flavour and water vapor transmission rates; and 3) to assess the use of edible coating to the quality of minimally processed durian, especially in inhibiting the release of durian flavour, during storage at low temperature. The result showed that low methoxy pectin (LMP)-cassein mixture-based edible film can be applied for minimally processed durian. Water vapor transmission rate (WVTR) of LMP-cassein mixture-based edible film (523.6 g/m2/day) was lower than that of LMP-soy protein isolate film. LMP- cassein mixture-based edible film added by stearic acid had WVTR between 383.66 and 491.75 g/m2/day. The WVTR of the film was 17.2 - 35.4% lower than that of the film without stearic acid. The optimum concentration of LMP and stearic acid in the formulation were 1% and 0.25%, respectively. Based on the entrapment capability of edible film to volatile compound of durian, i.e. its capability in inhibiting release of durian volatile compound, LMP-cassein mixture-based edible film added by 0,25% stearic acid was able to be applied in minimally processed durian. Decrease of water content of edible coated minimally processed durian (6.10%) was lower than that of minimally processed durian (18.11%) for 13 days storage at 5oC. Soluble solid decreasing rate of edible coated minimally processed durian was lower 2.5 times than that of minimally processed durian for 13 days storage at 5oC. Quantitative Descriptive Analysis (QDA) showed that the taste and aroma of edible coated minimally processed durian were not changed during storage at 5oC for 13 days. Their taste was dominated by sugar and honey sweet and their aroma was dominated with fruity, sweet and sulphury. On the other hand, the taste and aroma of non-edible coated minimally processed durian were changed, i.e. their sugar taste, and sweet and fruity aroma were decreased, and their sulphury and alcohol aroma were increased after 13 days storage at 5oC. Sulphur compounds of edible coated minimally processed durian, except diethyl-disulfide and ethyl-propyl disulfide, were decreased, during 13 day storage at 5oC. While alcane, keton, ester and acid compounds of edible coated minimally processed durian, except octane, butyric acid, palmitic acid, ethyl-2-methyl butanoate, isobutyl benzoate, methyl-3-hydroxy butanoate and ethyl dodecanoate, were increased. The rate of flavor compounds changes (increasing of 1,1-diethoxy ethane and 1-hexadecanol, and decreasing of 3,5-dimethyl-1,2,4-trithiolane, 3-hydroxy-2-butanone and ethyl-2-methyl butanoate) of edible coated minimally processed durian was lower than those of non-edible coated minimally processed durian after 13 days storage at 5oC. From the above results could be concluded that minimally processed durian using edible film made from 1% LMP, 1% casein and 0.25% stearic acid was suitable for storage at 5oC.

Durian merupakan salah satu buah-buahan yang mempunyai konsumen cukup besar. Selama ini konsumen sering sulit untuk memilih buah durian yang telah matang, sehingga sering kecewa setelah mengupasnya. Hal ini membawa konsekuensi untuk memasarkan buah durian yang telah diproses minimal (minimally processed durian), sehingga konsumen dapat melihat langsung kondisi daging buah dan dapat membeli sesuai dengan kebutuhan dan selera konsumen. Dibalik keuntungan tersebut, buah durian terolah minimal bersifat mudah rusak. Salah satu alternatif yang dapat dilakukan untuk menekan laju kerusakan buah durian terolah minimal serta memperpanjang masa simpannya adalah melapisi buah durian terolah minimal dengan pelapis yang dapat dimakan (edible coating) dikombinasikan dengan penyimpanan pada suhu rendah.