Nutty-like flavor production by Corynbacterium glutamicum 1220T from enzymatic soybean hydrolysate. Effect of encapsulation and storage on the nutty flavoring quality

Abstract

The main objective of this study was to evaluate the ability of Corynbacterium glutamicum to produce a safe nutty like flavor from enzymatic soybean meal hydrolysate (E-SH) and to investigate the effect of encapsulation and storage on the quality of the produced nutty flavoring. C. glutamicum was incubated with E-SH, supplemented and un-supplemented with a mixture of threonine and lysine. The generated volatiles of each culture were subjected to odor sensory analysis. The volatile compounds were analyzed by headspace solid phase microextraction (HS-SPME) and gas chromatography coupled with mass spectrometry (GC-MS). The sample showed the best nutty aroma and highest content of the most odorant compounds of nutty flavor was subjected to toxicity test and encapsulated in Arabic gum using spray drier. The stability of the encapsulated flavoring was evaluated during storage. A high correlation was found between the culture growth and consumed sugars. The odor intensity of the generated nutty-chocolate like aroma showed a gradual increase during incubation time. Pyrazines and 2/3- methylbutanal showed the highest content at the end of fermentation time. Encapsulation gave rise to a significant decrease in the branched aldehydes, which are responsible for the chocolate note of the flavoring sample. The high odor intensity of the stored sample was correlated to the significant increase in the pyrazines. The results of GC–MS analysis confirmed those of odor sensory evaluation of the nutty-like flavor.