Effects of phytase-supplemented fermentation and household processing on the nutritional quality of Lathyrus sativus L. seeds

Meseret Bekele Buta; Clemens Posten; Shimelis Admassu Emire; Ann-Katrin Meinhardt; Alexandra Müller; Ralf Greiner

doi:10.1016/j.heliyon.2020.e05484

Effects of phytase-supplemented fermentation and household processing on the nutritional quality of Lathyrus sativus L. seeds

Heliyon. 2020 Nov 11;6(11):e05484. doi: 10.1016/j.heliyon.2020.e05484. eCollection 2020 Nov.

Authors

Meseret Bekele Buta^{1

2

3

4}, Clemens Posten³, Shimelis Admassu Emire¹, Ann-Katrin Meinhardt², Alexandra Müller², Ralf Greiner²

Affiliations

¹ School of Chemical and Bioengineering, Department of Food Engineering, Addis Ababa Institute of Technology, P.O.B: 1176, Addis Ababa, Ethiopia.
² Department of Food Technology and Bioprocess Engineering, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Str. 9, 76131, Karlsruhe, Germany.
³ Institute of Process Engineering in Life Sciences III Bioprocess Engineering, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany.
⁴ College of Biological and Chemical Engineering, Department of Food Process Engineering, Addis Ababa Science and Technology University, P.O.B: 16417, Addis Ababa, Ethiopia.

Abstract

Grass pea (Lathyrus sativus L.) is commonly consumed in cooked, fermented, and roasted forms in Ethiopia. However, the impacts of household processing practices on its nutrients, antinutrients, and toxic compounds have not been adequately studied. Therefore, the effects of household processing and fermentation in the presence and absence of a phytase on the contents of β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP), myo-inositol phosphates, crude protein, minerals and the in vitro bioaccessibility were investigated. Fermentation exhibited a significant decline in β-ODAP (13.0-62.0%) and phytate (7.3-90.5%) irrespective of the presence of phytase. Pressure and pan cooking after discarding the soaking water resulted in a 27.0 and 16.2% reduction in β-ODAP. A 30% reduction in phytate was observed during germination followed by roasting. In addition, germination resulted in a significant (p < 0.05) increase in crude protein. Germination and germination followed by roasting resulted in the highest Fe bioaccessibilities (more than 25 fold higher compared to untreated samples) followed by pressure cooking and soaking. Processing also improved Zn bioaccessibilities by 50.0% (soaked seed without soaking water), 22.5% (soaked seed with soaking water), and 4.3% (germination). Thus, the processing technologies applied were capable of reducing the content of phytate (InsP₆) and β-ODAP with a concomitant increase in mineral bioaccessibilities. Processing of grass peas could therefore contribute to their more widespread utilization.

Keywords: Food analysis; Food science; Grass pea; Household processing; Mineral bioaccessibility; Myo-inositol phosphates; Phytase; β-ODAP.