Potential of the microalgae Nannochloropsis and Tetraselmis for being used as innovative ingredients in baked goods

The potential use of the microalgae species Tetraselmis and Nannochloropsis was investigated for the production of functional breads and crackers. Optimum flour substitution levels were 2.5% for baked crackers and 1.0 or 2.0% for breads containing Nannochloropsis or Tetraselmis, respectively. No major differences were observed in the physicochemical properties of the end products besides an expected darker and greener colour. Microalgae incorporation led to increased phenolic content and in vitro antioxidant capacity in both matrices. For example, the total phenolic content of crackers increased from 24.6 +/- 1.5 mg/100 g in the control to 32.4 +/- 0.4 or 34.2 +/- 1.0 mg/100 g in crackers containing Tetraselmis or Nannochloropsis, respectively. The amount of bioaccessible polyphenols after a simulated gastrointestinal digestion was also higher in microalgae-containing goods than in the controls. Sensory evaluation showed that microalgae-containing products were competitive with the controls with the added advantage of having an improved nutritional value and a trendy ingredient. Moreover, microalgae-containing products showed an increased emission of some volatile compounds such as p-cymene and (Z)-2-heptenal, which are responsible for fresh, citrus, terpenic, woody, and spicy or fatty, oily, and fruity odours, respectively.