The fermentation efficiencies and ethanol production in the hydrolysates of fruit samples are presented in Table 3.Ethanol yield in fruit pulps varied significantly between the fruit samples and the highest yield was 35.86% in themixed fruit pulps sample, followed by 28.45% in banana pulp and the lowest yield was 26.5% in mango pulp. Thefermentation of enzymatic hydrolysate of acid pretreated mixed fruit pulps (banana and mango) by yeast showed anincubation period of 48 h as optimum for maximum ethanol of 35.86% corresponding to a fermentation efficiency of70.33%. In peels samples, the maximum yield was 13.84% in banana and 9.68% in mango at 42 h of incubation. Theresults on ethanol yield are in concert with the observations of Sirkar et al. [36] in banana. The fermentation studies onthe hydrolysates of fruit pulps obtained from both the pretreatments (LHW & DAP) with out enzymatic hydrolysishave showed poor ethanol yield and the ethanol yield was 25% lower than the normal fermentation process ofhydrolysates obtained after saccharification (Fig 2). The results are in good agreement with the previous report ofHammond et al. [6], where he has reported a ethanol yield reduction of 13.4% from the ripen banana pulp withoutenzymatic hydrolysis. Joshi et al. [51] in a fermentation study with flocculating yeast (S. uvarum) observed that wastebanana peels are capable of providing enough sugar for the fermentation and hence can be economically utilized forethanol production. Onwuka and Awam [12] have reported 19 24% of fermentable sugar and alcohol content of 881.5 brix (9.96 11.25%) in cooking banana and plantain.The fermentation studies showed a maximum ethanol productivity of 0.747% h in mixed fruit pulps and minimum of0.230% h in mango fruit peels (Table 3). A steep increase in the ethanol productivity over the increase of yeast cellgrowth was also observed and the highest ethanol yield was observed when the yeast biomass was recorded as 10.23 gL , 4.06 g L during the fermentation of mixed fruit pulps and peels respectively (Fig 3). Similarly for banana andmango fruit pulps the yeast growth was maximum at 48 h incubation and for fruit peels the maximum yeast growthwas observed at 42 h incubation (Fig 4 & 5). Previous reports showed a fermentation period of 36 h as optimum forethanol production in water hyacinth [52] and 24 h for acid and enzymatic hydrolysate of agricultural wastes by cerevisiae[22]. A rapid bioconversion of sugars to ethanol during the initial stages could also be observed in all thefruit samples from the increased cell mass of yeast and also from the decreasing trend in the amount of residual sugarsin the fermentation medium (Fig 3 - 8). This observation is consistent with the report of Akin-Osanaiye et al. [53],which indicated that the amount of yeast influenced ethanol production in Carica papaya agro wastes. The decline inthe ethanol production beyond 48 h of incubation in fruit pulps and 42 h of incubation in fruit peels might be probablydue to reduced substrate concentration or due to decrease in the number of viable yeast cells or because of thedenaturation of enzyme by the ethanol produced during fermentation. The current observations are in good agreementwith similar results reported by Pramanik and Rao [5] in grape waste. The reduction in the alcohol yield in mangomight be due to the inhibitory effect of high polyphenol content and or less availability of fermentable sugar after evensaccharification. A maximum concentration of ethanol from mango pulp (7 8.5%) was reported by Reddy and Reddy[54] using yeast fermentation. It is comparably low with the current findings on ethanol production from mango.