Effects of selected lactic acid bacteria on the characteristics of amaranth sourdough.
BACKGROUND
As the processing of amaranth in baked goods is challenging, the use of sourdough fermentation is a promising possibility to exploit the advantages of this raw material. In this study the fermentation properties of Lactobacillus plantarum, Lactobacillus paralimentarius and Lactobacillus helveticus in amaranth-based sourdough were examined in order to validate them as starter cultures. pH, total titratable acidity (TTA) and lactic/acetic acid ratio of the sourdough and sensory properties of the resulting wheat bread were evaluated using fermentation temperatures of 30 and 35 °C.


RESULTS
While fermentation pH, TTA and lactic acid concentration showed small variations with the use of L. plantarum and L. paralimentarius, L. helveticus reached the most intensive acidification after initial adaptation to the substrate. Acetic acid production was independent of lactic acid metabolism. Furthermore, the lactic/acetic acid ratio exceeded recommendation by 10-35 times (fermentation quotient 25-82). Sensory evaluation showed no significant differences between the two fermentation temperatures but differences among the three micro-organisms.


CONCLUSIONS
The results provide relevant information on the fermentation properties required of a customised starter for amaranth flour.
Jekle
Mario
M
Institute of Brewing and Beverage Technology, Workgroup Cereal Process Engineering, Technische Universität München, Weihenstephaner Steig 20, D-85354 Freising, Germany. mjekle@wzw.tum.de
Houben
Andreas
A
Mitzscherling
Martin
M
Becker
Thomas
T
D019342:Acetic Acid / Q000378:metabolism; D027721:Amaranthus / Q000737:chemistry*; D001939:Bread / Q000032:analysis* / Q000382:microbiology*; D055598:Chemical Phenomena; D015169:Colony Count, Microbial; D055050:Diet, Gluten-Free; D005260:Female; D005285:Fermentation; D005511:Food Handling; D005516:Food Microbiology; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism; D007778:Lactobacillus / Q000254:growth & development / Q000378:metabolism*; D052198:Lactobacillus helveticus / Q000254:growth & development / Q000378:metabolism; D048191:Lactiplantibacillus plantarum / Q000254:growth & development / Q000378:metabolism; D008297:Male; D012639:Seeds / Q000737:chemistry*; D012677:Sensation
D019344:Lactic Acid; D019342:Acetic Acid