Plackett-Burman design was used to efficiently select important medium components affecting the lipase production by Aspergillus niger using shea butter cake as the main substrate. Out of the eleven medium components screened, six comprising of sucrose, (NH4)2SO4, Na2HPO4, MgSO4, Tween-80, and olive oil were found to contribute positively to the overall lipase production with a maximum production of 3.35 U/g. Influence of tween-80 on lipase production was investigated, and 1.0% (v/w) of tween-80 resulted in maximum lipase production of 6.10 U/g. Thus, the statistical approach employed in this study allows for rapid identification of important medium parameters affecting the lipase production, and further statistical optimization of medium and process parameters can be explored using response surface methodology.

The physicochemical (colour, bulk density, thermal properties, molecular sizes), functional (water and oil absorption, solubility, emulsifying and gelation properties) and secondary structural properties of winged bean isolate (W-ISO) were studied and compared with those of soybean isolate(S-ISO) as reference. Results showed that W-ISO and S-ISO had extraction rates of 32.23 and 37.52 g/100 g, respectively, with corresponding protein content of 81.68 and 85.69% (dry weight basis). W-ISO and S-ISO had denaturation temperature and enthalpy of 105.53 & 111.61 °C, and 3.77 & 3.30 J g-1,respectively. Both isolates showed comparable functional properties, but W-ISO had higher foaming and oil absorption properties whereas S-ISO had higher water absorption and surface hydrophobicity. FTIR spectroscopy showed that W-ISO is composed of 15.38% α-helices, 37.46% β-sheets, 31.67% turns and 15.38% disordered secondary structures whereas S-ISO had 15.46% α-helices, 46.15% β-sheets, 30.78% turns and 7.69% unordered components. In addition to being a potential food ingredient comparable to soybean isolate, winged bean isolate can also be employed in foods where high foam volume is essential.

This study was carried out to formulate rice and pigeon pea flour blend with the aim of providing nutrient‐enriched and inexpensive food for developing countries where the raw materials are found in abundance. Three factors (screw speed, feed moisture content and feed blend composition) affecting the extrusion cooking process were subjected to face‐centred central composite design (FCCCD), and physical properties were used as the response. Analysis of variance showed that the developed quadratic model was significant with coefficient of determinations (R2) of 0.96 for expansion index, 0.93 for bulk density and 0.88 for water absorption index. Validation experiments were carried out where four rice–pigeon pea flour blends were subjected to physical, mineral and amino acid analyses. Formulation 3 set at screw speed, feed moisture content and feed blend composition of 220 rpm, 30% and 25%, respectively, led to maximum expansion index of 9.98 ± 0.15, bulk density of 0.12 ± 0.01 g/mL and water absorption index of 6.41 ± 0.07. There was significant (p < 0.05) increase in essential amino acids in all the developed rice–pigeon pea flour blends, and Formulation 3 was found to be two‐ and fivefold higher in terms of methionine and lysine contents, respectively, than the control (extruded rice). Similarly, calcium (3.41 ± 0.07 mg/100 g), iron (12.64 ± 0.03 mg/100 g) and zinc (9.33 ± 0.02 g/100 g) contents in Formulation 3 were significantly (p < 0.05) higher than the values of 1.19 ± 0.13, 5.89 ± 0.10 and 2.67 ± 0.05 mg/100 g recorded, respectively, for the extruded rice (control). In conclusion, the extruded rice–pigeon pea flour blend showed better physical properties and nutritional quality than the extruded rice.

Xylanases are hydrolytic enzymes produced by different microorganisms which convert xylooligomers to its constituent xylose units. The growing interests in xylanase production could be linked to its diverse industrial applications. The use of agricultural residues contributed in overcoming one of the major challenges of enzyme production, which is the production cost. This study involves the use of Face centered central composite design (FCCCD) under Response surface methodology (RSM) to optimize the medium components for enhanced xylanase production using soybean hulls as renewable substrate by solid state fermentation. The optimum components that led to maximum xylanase activity of 139.73 U/g were 0.58% w/w of urea, 0.03% w/w of K 2 HPO 4 and 0.04% w/w of Na 2 CO 3. Coefficient of determination (R 2) used to check the fitness of the model showed the correlation between the experimental and predicted responses with a value of 0.8981. Thus, this study showed the potential use of soybean hulls for xylanase production Keywords optimization, renewable substrate, soybean hulls, xylanase.