دانلود رایگان مقاله انگلیسی ذخیره سازی دسته غلات فرموله شده با آرد پوست موز؛ ترکیب زیست فعال و ساختار های بافتی - امرالد 2017

Abstract

Purpose – This paper aims to examine the bioactive compounds and texture properties of cereal bars formulated with banana peel flour during storage. Design/methodology/approach – Seven cereal bars were produced and stored during 11 months, under vacuum and protected from the light. The total phenolic compounds, the activity antioxidant by ABTS [2,20 - Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] method, the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) method expressed as EC50 (concentration required to reduce the original amount of free radicals by 50 per cent) and texture properties were evaluated over the storage period. Findings – In general, total phenolic compounds decreased during storage (from 4.19 to 1.11 mg GAE. g-1f.w.). Although the total antioxidant activity (ABTS method) increased during the fifth month, it reduced during storage (from 3.41 to 0.30 mmol TE.g-1f.w.); and the EC50 was not modified in many formulations, though it decreased in other formulations during storage period (from 3913 to 19221 g fruit.g-1 DPPH). The force of rupture began to increase in the fourth month (reaching 62.4 N), and hardness began to increase in the ninth month (reaching 444 N). The formulation and time factors influenced the total phenolic compounds, total antioxidant activity (ABTS method), force of rupture and hardness, while EC50 was only influenced by the formulation (p-value = 0.001). A principal component analysis showed that time had little effect on the most important characteristics considered in description of the cereal bars. Originality/value – Cereal bars can be consumed up to the third month of storage, considering the texture of the products. Moreover, the presence of bioactive compounds in cereal bars depends on the addition of banana peel flour, which it contributes to the insertion of total phenolic compounds and total antioxidant activity in cereal bars, aggregating functional properties in these products.

4. Conclusion

Effects of time on phenolics compounds, antioxidant activity and texture properties were not the same for all formulations of cereal bars formulated with banana peel flour. The quantity of total phenolic compounds in some cereal bars decreased over the period of storage, though it increased in another formulation. Total antioxidant activity, which was measured using the ABTS method, increased in the fifth month, but it then decreased until the last month. In addition, total antioxidant activity decreased in almost all of the formulations over the course of the storage period. The antioxidant activity measured using the DPPH method was not modified in many formulations, though it decreased in some formulations. The texture properties of the cereal bars changed during storage, with an increased force of rupture starting in the fourth month and with increased hardness starting in the ninth month. Although time did affect total phenolic compounds, antioxidant activity and texture properties of cereal bars during storage, the PCA showed that time had little effect on the most important characteristics used to describe cereal bars: the formulations were described by almost the same characteristics at the beginning and at the end of the storage period. Considering the texture, we can observe that the cereal bar with the addition of banana peel flour can be consumed up to the third month of storage, due to the high increasing on the force of rupture at the fourth month, although studies about sensory acceptability should be performed to evaluate this increment. However, considering the bioactive compounds, consumption of the cereal bars can be done up to the fifth month, based on results for total phenolic compounds and total antioxidant activity measured through ABTS method. Finally, the presence of bioactive compounds in cereal bars depends on the addition of banana peel flour, which contributes to the insertion of total phenolic compounds and the antioxidant activity in cereal bars and therefore aggregates functional properties in the products.