African Journal of
Food Science

  • Abbreviation: Afr. J. Food Sci.
  • Language: English
  • ISSN: 1996-0794
  • DOI: 10.5897/AJFS
  • Start Year: 2007
  • Published Articles: 781

Full Length Research Paper

The effect of mechanical kneading and absit preparation on tef injera quality

Yoseph Legesse Assefa
  • Yoseph Legesse Assefa
  • Food Engineering Graduate Program, School of Chemical and Bioengineering, Addis Ababa Institute of Technology, Addis Ababa University, P.O. Box 385, Addis Ababa, Ethiopia.
  • Google Scholar
Shimelis Admassu Emire
  • Shimelis Admassu Emire
  • Food Engineering Graduate Program, School of Chemical and Bioengineering, Addis Ababa Institute of Technology, Addis Ababa University, P.O. Box 385, Addis Ababa, Ethiopia.
  • Google Scholar
Workineh Abebe
  • Workineh Abebe
  • Ethiopian Institute of Agricultural Research, P.O. Box 2003, Addis Ababa, Ethiopia.
  • Google Scholar
Marina Villanueva
  • Marina Villanueva
  • College of Agricultural and Forestry Engineering, University of Valladolid, Av. Madrid 57, 34004 Palencia, Spain.
  • Google Scholar
Felicidad Ronda
  • Felicidad Ronda
  • College of Agricultural and Forestry Engineering, University of Valladolid, Av. Madrid 57, 34004 Palencia, Spain.
  • Google Scholar


  •  Received: 09 May 2018
  •  Accepted: 17 August 2018
  •  Published: 31 October 2018

Abstract

The aim of this study was to investigate the effect of mechanical kneading and ‘absit’ preparation difference on the quality of tef injera, the staple food of Ethiopians. Standard methods were adopted to determine the starch fraction, total phenol, flavonoid, phytate and tannins of injera. Sensory injera quality was assessed using 9-point-hedonic scale. Change in kneading conditions (time/speed) did not significantly affect the free sugar (FSG), slowly digestible starch (SDS), resistant starch (RS), total starch(TS) and starch digestion rate index (SDRI). On the other hand, significant variation was observed in rapidly available glucose and rapidly digestible starch (RAG and RDS). Flavonoids, total phenolics and phytate contents varied significantly at different kneading time- speed combinations. Injera sensory quality was also significantly affected due to change in kneading conditions. Kneading condition 5 (3 min at speed 6) has the highest injera overall acceptability while kneading condition 9 (7 min at speed 12) had the lowest. In addition to kneading conditions, absit preparation (water to fermented dough ratio) was also found to affect the quality of tefinjera. Absit # 3 made from 100 ml of fermented dough and 900 ml of water had the highest injera overall acceptability while, the lowest was observed on Absit # 4 made from 300 ml of fermented dough and 100 ml of water. In conclusion, both kneading and absit preparation significantly influenced starch hydrolysis, flavonoids, total phenolics and phytate contents as well as sensory quality of injera.

 

Key words: Kneading, sensory quality, absit preparation, starch fractions.