Abstract:

Solid-phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS) was
employed to analyze the volatile flavor compounds of skim milk yoghurts fortified with ganoderic acid or Ganoderma
lucidum polysaccharide (GLP), which were designated as GLA yogurt and GLP yoghurt, respectively. Results showed that
compared with control yogurt, the viable cell counts of lactic acid bacteria in GLP yogurt and GLA yogurt were increased
by 3.1 and 1.5 times. GLP significantly promoted the multiplication and growth of Streptococcus thermophilus and
Lactobacillus plantarum. A total of 24 volatile flavor compounds were identified in control yogurt while 37 and 30 volatile
flavor compounds in yoghurts supplemented with 0.12% GLP and 0.09% GLA, respectively, mainly including ketones,
aldehydes, acids, alcohols, and esters. Compared with control yogurt, the contents of ketones, aldehydes and alcohols in
GLP yogurt were reduced by 14.15%, 3.00% and 10.35% whereas the contents of esters and hydrocarbons were increased
by 14.01% and 10.42%，respectively; the contents of ketones, acid and alcohol compounds in GLA yogurt were reduced by
4.78%, 2.22% and 8.93%, respectively, whereas the contents of aldehyde and ester were increased by 5.31% and 10.61%,
respectively. The current study showed that the number of volatile flavor compounds in yogurt was increased and the
functional quality was improved by the addition of either ganoderic acid or GLP.

Key words: Ganoderma lucidum polysaccharide, ganoderic acid, lactic acid bacteria, aroma, solid-phase micro extractiongas chromatography-mass spectrometry (SPME-GC-MS)