Development and evaluation of polyphenol- and dietary fiber-enriched functional drink on cognitive function and mood in working-age volunteers

INTERVENTION: Placebo Comparator Other,Experimental Other,Experimental Other Placebo,Low dose of the functional drink,High dose of the functional drink Subjects received the placebo product which has the same color and smell and looks like the functional drink.,Subjects received the functional drink contained 36.6% guava juice & mint syrup.,Subjects received the functional drink contained 73.2% guava juice & mint syrup. CONDITION: functional drink ; cognitive function ; mood ; working‐age volunteers Healthy condition ; functional drink ; cognitive function ; mood ; working‐age volunteers PRIMARY OUTCOME: cognitive enhancing effects 2 months measured Event‐Related Potentials (ERPs) SECONDARY OUTCOME: Neurotransmitters in serum: MAO, MAO‐A, MAO‐B, GABA‐T, GAD, AChE 2 months laboratory,Proinflammatory IL‐1beta TNF‐alpha IL6 2 months laboratory,Brain‐derived neurotrophic factor (BDNF) and cortisol level in serum 2 months laboratory,Levels of SCFA, lactate, Lactobacillus spp. and Bifidobacterium spp. in feces 2 months laboratory,The changes of hematological and clinical chemistry parameters 2 months laboratory,Phenolic compounds and flavonoids content in serum 2 months laboratory INCLUSION CRITERIA: 1. Healthy, working‐aged, volunteers between the ages of 20 and 40 year 2. BMI 18.5‐25 kg/m2 3. All volunteers did not consume tea, coffee, chocolate, and alcohol for at least 12 hours before as well as during the trial.