Textural Hardness of Selected Ugandan Banana Cultivars under Different Processing Treatments

Abstract

Textural hardness affects cooking time, processing, fuel used and the quality of cooked bananas. In this study, textural hardness of selected Ugandan cooking and juice banana cultivars at green maturity was determined using a Texture Analyzer in raw form and at 30, 50, 70, 90, 100 and 130 min in boiled, steamed, mashed and cooled forms.Raw juice bananas (JB) were significantly harder (36.17N to 42.43N) than raw cooking bananas (CB) (22.37N to 26.72N) (p<0.05). On cooking, JB were harder than CB irrespective of cooking method and time. Boiling and steaming rapidly decreased hardness of the bananas in the first 30 min and decreased slowly thereafter. Boiling produced softer bananas than steaming while mashing resulted in intermediate hardness. Amongst JB, Kayinja was significantly harder than Ndiizi and Kisubi in boiled and steamed forms (p<0.05). Hardness of CB was not significantly different (p>0.05) for all cooking treatments, but Kibuzi was consistently softer while Kazirakwe and Nakabululu were harder than other CB cultivars.Cooling significantly increased (p<0.05) hardness of bananas under all treatments with JB being harder in all cases. Mashed and steamed bananas were harder than boiled bananas when cooled. Bananas cooked longer had lower hardness regardless of cooking method.Overall, textural hardness decreases with cooking time regardless of cooking method. Boiled bananas are softer than mashed or steamed. Cooling increases hardness which follows first order kinetics. Therefore, bananas should either be boiled or steamed and mashed for softer texture and be eaten within 30 min of serving. Juice bananas should not be cooked because of the hard texture established in this study.

Starch and Pectin Affect Hardness of Cooked Bananas

“…Pectinase treated juice bananas were harder than cooking bananas. This is because juice bananas contain more starch than cooking bananas (Gafuma et al, 2018) which means the more starch in the bananas, the harder the texture as evidenced in this work. In all cases, hardness reduced with cooking time between 50 and 130 min but still the pectinase-treated bananas remained significantly harder than the controls.…”

“…For each of starch and pectin treatments, 0 (0%), 1 (1.7%), 3 (5%), 5 (8.3%), and 7 g (11.7%) of banana starch extracted from Nakitembe according to the protocol of Gafuma et al (2018) and pectin (Sigma) were weighed separately. Approx.…”

“…The bananas were cooked by steaming in a Food Steamer for 30 min as in section 2.3 before being mashed. The mashed bananas were placed back into the steamer and steamed for a further 20 min (50 min of cooking overall) before sampling for texture analysis (Gafuma et al 2018). The remaining banana masses were treated as in section 2.3 before being used to measure texture of the cool samples.…”

“…Textural hardness analysis was performed using a Texture Analyzer (TA.XT plus stable micro-systems, Surrey, UK) according to the method of Gafuma et al (2018). Cohesiveness was defined as the ratio of the area under the second penetration curve to the area under the first penetration and values were generated by the Texture Analyzer according to the manufacturer's instructions (Texture technologies Corp. and Stable Micro Systems, 2018).…”

“…When cooked, bananas soften but upon cooling, they irreversibly become hard. The tendency of cooked banana texture to harden during cooling has been objectively proven by Gafuma, Byarugaba-Bazirake, & Mugampoza (2018).…”