Identification of lactic acid bacteria constituting the predominating microflora in an acid-fermented condiment (tempoyak) popular in Malaysia

Effect of temperature-controlled fermentation on physico-chemical properties and lactic acid bacterial count of durian (Durio zibethinus Murr.) pulp

“…Table 1 shows the pH of durian pulp before and during fermentation at three different incubation temperatures. The pH at Day 0 (control) of fermentation was pH 6.92, and was slightly higher compared to previous findings which reported that the pH of fresh durian ranged pH between 6.63-6.83 (Leisner et al 2001) and 6.70 (Amiza et al 2006). There was no significant difference (p>0.05) in the pH (pH 6.92-7.19) when incubation was done at 15°C temperature for 10 days, and the aroma profile of fresh durian pulp was still retained.…”

“…The initial titratable acidity (TA) of durian pulp, expressed as percent lactic acid, was 0.07 % (Table 1), and was high compared to the previous study (0.03 %) reported by Leisner et al (2001) but was low (0.71-0.89 %) to that reported by Amin et al (2004). Differences in the findings may be due to different variety of fruit being used.…”

“…However, the pH at 27 and 40°C decreased rapidly during the first 2 days and thereafter declined gradually until pH 4.13 and 4.30, respectively, on Day 10, with no significant difference (p>0.05) between these values. In comparison, the pH values of fermented durian obtained from the local market in Malaysia were between pH 4.0 and 4.2 (Leisner et al 2001), indicating a long fermentation time. The decrease in pH caused the pulp to acquire a sour taste.…”

“…Leisner et al (2001) reported that 64 LAB isolates could be found fermented durian pulp including homo and heterofermentative bacteria. Majority of these isolates were homofermentative bacteria and were identified as Lactobacillus plantarum, Lb.…”

“…Previous studies on fermented durian pulp have been heavily focused on microbiological aspects (Amiza et al 2006;Amin et al 2004;Leisner et al 2002Leisner et al , 2001) and flavor constituents (Neti et al 2011;Yuliana and Garcia 2009), however, its physico-chemical properties during fermentation have not been investigated widely. A previous study reported that microorganisms in durian pulp were susceptible to heat treatment (Amiza et al 2006).…”