A Group of IPB Researchers Developed Methods to Maintain the Quality and Prolong Shelf Life of Tempoyak

Tempoyak is a dish which originated from the fermented durian (Durio zibethinus Murr.) . Tempoyak usually consumed as a side dish of rice. It can also be eaten directly but this is rarely done, because the acidity and aroma of tempoyak itself. Tempoyaks are usually made during the durian season, when the abundance of durian and excess production are made into fermented tempoyak. As a fermented food, the tempoyak-making process involves a number of different lactic acid bacteria. Tempoyak has a short shelf life.

The researcher of the Department of Agroindustrial Technology, of the Faculty of Agricultural Technology, Bogor Agricultural University (IPB), Dr. Ir. Endang Warsiki explained that the decrease of tempoyak quality can be influenced by several things. Fast-growing fermentation rates have resulted in alcohols with carbon dioxide (CO2) by-products. High alcohol content is not desirable on temptoak because it can damage the taste image.

"In addition to the rapid fermentation rate, food packaging systems is another factor  that cause damage and decay on the tempoyak. The inappropriate food packaging systems will  accelerate the degradation of tempoyak quality, which is physically characterized by discoloration, odour of alcohol and the presence of insects such as maggots," she said.

The global food packaging industry has a lot to contribute not only in addressing food losses but also in ensuring food safety as well as enhancing global food trade, which is a key to economic development of varying economies. Modified processing and packaging improvements are expected to maintain quality and extend shelf life. She and her fellow researchers, namely Rapeka Reli and Mulyorini Rahayuningsih tried to modify the processing of fermentation of tempoyak. The pasteurization and packaging improvement could be expected to maintain the quality and extend the tempoyak's shelf life.

"Good quality durian flesh is fermented in polyethylene terephthalate (PET) plastic containers and incubated at room temperature, then tempoyak pasteurized at 650C for 30 minutes. Then tempoyak were packed using PET plastic and polyamide, with vacuum and non-vacuum packing. The  pasteurized  and  non- pasteurized  tempoyak  were  packed  using  PET (Polyethylene terephthalate) and polyamide plastics. MAP (Modified Atmosphere Packaging) was used for PET, where O2 and CO2 level were  5% to 6% and 67% to  69%,  respectively.  Meanwhile,  vacuum  packaging  technique  was  applied  in polyamide  plastic.  The  tempoyak  was  then  stored  at  room  temperature. The parameters  used  for  end  product  of  tempoyak  were  similar  to  fresh  tempoyak, with alcohol measurement as additional parameter," she said.

The study revealed that the best quality of tempoyak was produced by product with pasteurization treatment. Lactobacillus genus with L. plantarum, L. casei, and L. fermentum were the dominant species of lactic acid bacteria. Dr. Endang explained that after tempoyak was fermented for 84 hours then pasteurization process was carried out to slow the rate of fermentation. After 84 hours of fermentation, then the pasteurization should be conducted to stop the fermentation. The 84th hours was the constant phase, it was the right time to inhibit the acid lactic bacteria growth.

PET and polyamide-related packaging have no effect on product shelf life, while MAP packaging techniques provide better protection compared to vacuum processes.

"Pasteurized tempoyak packaged in PET with MAP technique had the longest shelf life as much as 84 days, compared to others treatment which was t only 14 - 56 days," she said. (Wied)

Published Date : 14-Mar-2018

Resource Person : Dr. Ir. Endang Warsiki

Keyword : A Group of IPB Researchers Developed Methods to Maintain the Quality and Prolong Shelf Life of Tempoyak