Comprehensive study of matcha foam formation: Physicochemical composition analysis and mechanisms impacting foaming...

Tea foam is crucial for new food and drink innovations. This study examined nine types and grades of matcha, identifying Longjing 43 as a high-quality raw material for matcha with good foaming properties. Foam scanning, particle electrophoresis and biochemical analysis revealed that pH (≈6.0), catechins (such as EGCG), amino acids (such as valine), pectin, soluble proteins and lipids enhanced foam formation. These components affected matcha's foaming through inter-component complexation, hydrophobic interaction of groups and intermolecular hydrogen bonds. EGCG had the greatest impact on foaming ability (1.89-fold), while amino acids primarily stabilized the foam. At the molecular level, phenolic hydroxyl groups close to each other promoted foaming, whereas alcoholic hydroxyl groups had the opposite effect. Phenol (5.17-fold) and n-propanol (8.03-fold) were the most effective foam promoters among phenols and alcohols. This study enhances our understanding of tea foam's biochemical mechanisms, driving innovation in food and beverage products.