Okafor N, Umeh C, Ibenegbu C, Obizoba I, Nnam N
Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, Awka, Nigeria.
Int J Food Microbiol. 1998 Mar 3;40(1-2):43-9. doi: 10.1016/s0168-1605(98)00011-7.
Lactobacillus delbruckii, Lactobacillus coryneformis, and a Saccharomyces sp., previously found among 214 isolates to be the highest producers of linamarase, amylase, and lysine were inoculated separately or mixed into cassava mash and fermented with, or without dewatering, for 24, 48, 72, 96 and 120 h. At the end of the fermentation period, the mash was converted to garri by heating over a gas burner. The mash and the garri resulting from it were assessed for lysine and residual cyanide, while the garri was also studied for its organoleptic properties. The inoculation of the microorganisms into cassava mash produced a sharp drop in the cyanide content of the mash, particularly when the mixture of organisms was inoculated into undewatered cassava mash rather the single organisms. After 24 h, while the cyanide content of the control (uninoculated mash) mash was 3.06 microg/g in the dewatered mash, and 4.24 microg/g in the undewatered mash, the inoculation of a mixture of the three organisms caused the cyanide content in the inoculated mashes to drop by 150% to 1.96 microg/g (dewatered mash) and by 300% to 1.43 microg/g (undewatered mash). It also appears that the process of producing the garri from the mash by heating, caused a further reduction of the cyanide content: thus the garri always contained less cyanide than the mash from which it was made. The lysine content of the mash was also highest when all three organisms were mixed; it also tended to increase with increasing length of fermentation of the mash. Whereas the single organism most effective in reducing the cyanide content of mash was Lactobacillus delbruckii, in the case of lysine production, it was the yeast. The organoleptic properties of the garri which were assessed were flavour, texture, colour and general acceptability. In general these properties were superior at the P < 0.01 level in garri made from the undewatered mash in comparison with that from dewatered mash, especially when the mixture of organisms was used. The inoculation of the mixture of the three organisms produced a dramatic reduction in the time (24 h) taken for the highest 'general acceptability' score to be given by the tasters when compared with the singly inoculated organisms and the control, which attained this characteristic after about 96 h of incubation in mash.
德氏乳杆菌、棒状乳杆菌和一种酿酒酵母，此前在214株分离菌中被发现是最高产的亚麻苦苷酶、淀粉酶和赖氨酸的产生菌，它们被分别接种或混合到木薯泥中，在有或没有脱水的情况下发酵24、48、72、96和120小时。在发酵期结束时，通过在燃气炉上加热将木薯泥转化为加里（一种木薯制品）。对木薯泥及其制成的加里进行赖氨酸和残留氰化物的评估，同时也对加里的感官特性进行研究。将微生物接种到木薯泥中会使木薯泥中的氰化物含量急剧下降，特别是当将混合菌接种到未脱水的木薯泥中而不是单一菌种时。24小时后，在脱水木薯泥中，对照（未接种的木薯泥）的氰化物含量为3.06微克/克，在未脱水木薯泥中为4.24微克/克，接种三种菌的混合物会使接种木薯泥中的氰化物含量下降150%至1.96微克/克（脱水木薯泥）和300%至1.43微克/克（未脱水木薯泥）。似乎通过加热从木薯泥生产加里的过程会导致氰化物含量进一步降低：因此加里中的氰化物含量总是比其制作原料木薯泥中的少。当三种菌混合时，木薯泥中的赖氨酸含量也最高；它也倾向于随着木薯泥发酵时间的延长而增加。在降低木薯泥中氰化物含量方面最有效的单一菌种是德氏乳杆菌，而在赖氨酸生产方面，最有效的是酵母。对加里评估的感官特性包括风味、质地、颜色和总体可接受性。总体而言，与脱水木薯泥制成的加里相比，在P < 0.01水平上，未脱水木薯泥制成的加里的这些特性更优，特别是当使用混合菌时。与单独接种的菌种和对照相比，接种三种菌的混合物使品尝者给出最高“总体可接受性”评分的时间大幅缩短（24小时），对照在木薯泥中培养约96小时后才达到这一特征。
