Development of composite flour
Three combinations of whole cowpea pod, barley husk and wheat flour were tried for the development of composite flour. Of the 3 developed flours, flour having 20% incorporation of barley husk powder and cowpea pod powder (1:1 ratio) was selected for further study due to its high sensory quality. (Table 1 and 2).
Proximate composition
Table 3 shows the proximate composition of the selected composite flour and barley husk. The composite flour was found to have lower moisture content when compared with the values reported by
Bhatt and Gupta (2015) that is 12.5 per cent. Whereas barley husk had higher moisture content in comparison to that one found by
Biswas et al., (2017). In comparison to the current study,
Jothilakshmi et al., (2016) observed the total ash content to be lower (1.7 g) and crude protein to be higher (15.15 g) in multigrain mix as compared to the total ash and crude protein content of composite flour in the study.
Garrote et al., (2008) estimated ash and protein content in barley husk. The ash content was found to be 19.81 per cent which was higher than the ash content in the current study. The crude protein in wheat husk was 6 per cent according to the study of
Bledzki et al., (2009) which was found to be lower while the crude fat was higher than that reported in the present study. Similar results were found by
Bhatt and Gupta (2015) in their study on composite flour. When compared with the study of
Malshe et al., (2014), the crude fibre content in composite flour was found to be same whereas physiological energy was observed to be higher. In contrast,
Ekwe (2013) found higher crude fibre content in rice husk as compared with the fibre content of barley husk in the present study. Carbohydrate in composite flour evaluated by
Itagi and Singh (2012) was found to be higher than the results obtained in the present study
Ekwe (2013) observed a lower physiological energy and carbohydrates content in rice husk in comparison to the results of barley husk in the present study.
Micronutrient composition
The micronutrient analysis of composite flour and barley husk is shown in Table 4. According to
Adegunwa et al., (2017) the phosphorus content of composite flour was higher in comparison to the results of present study. The iron content in composite flour and barley husk was found to be higher when compared with the results of
Tangariya et al., (2018) and
Raheem and Kareem (2017) respectively. The magnesium, calcium and manganese content in composite flour was found to be lower in comparison to the study of
Bhatt and Gupta (2015),
Tangariya et al., (2018) and
Yuvarani et al., (2016). The phosphorus, magnesium, calcium and iron values were found to be higher in barley husk, when compared with the results of
Raheem and Kareem (2017),
Hashim et al., (1996), Slither (2008) and
Korotkova et al., (2016).
Table 5 shows the total dietary fibre content of composite flour and barley husk. The total dietary fibre in multigrain flour prepared by
Pande et al., (2017) was found to be similar as reported in the current study that is 21.89 per cent.
Fadaei and Salehifar (2012) found higher value of dietary fibre in rice husk (44.66g) than that of barley husk evaluated in this study.
Antinutrients
The results showed that the phytic acid content of composite flour (191.05 mg) differs significantly from that of barley husk (3.66 mg)
Parmar and Dahiya (2013) analyzed the phytic acid in wheat flour ( between 167.18 to 241.63 mg), which was similar to the result of the present study.
Perea et al., (2019) measured the phytic acid level in barley husk and found it to be 2.32 mg, which was higher than the value reported in this study. Tannins content of composite flour was 2.38 mg whereas in barley husk, it was found to be 5.04 mg.
Bhatt and Gupta (2015) analyzed the tannin content of composite flour in their study which was 0.159 per cent and was lower than the result of present study.
Chikwendu et al., (2014), studied the tannin content in cowpea husk (3.05 mg) which was lower than that of barley husk in the study (Table 6).
Antioxidants
Total phenolic content of composite flour and barley husk was 438.44 mg of GAE/g and 302.84 mg of GAE/g respectively. The difference between the two was significant. When compared to the study of
Tangariya et al., (2018) the total phenolic content (549.70 mg of GAE/g) was higher than that reported in current study. However total phenolic concentration in barley husk was similar to that of
Perea et al., (2019). Total flavonoid content in composite flour and barley husk was 24.55 mg of RE/g and 35.08 mg of RE/g respectively. The values differed significantly. Total flavonoid content of composite flour was higher than that reported in the study of
Bhatt and Gupta (2015) i.e 48 µgQE/mg. The total flavonoid content of barley husk was higher than that reported by
Perea et al., (2019) (Table 7).
Storage stability of composite flour
The study revealed that both the packaging materials are shelf stable up to 90 days. However, laminated aluminum pouches gave better results.
Statistical analysis revealed significant difference between composite flour and barley husk in overall nutritional estimations.