Improving chestnut physicochemical properties through fermentation - Development of chestnut Amazake.

The increased awareness of population regarding the impact of consumption habits is leading to interest in new, innovative, diversified and health promoting foods. In this work, two new amazake fermented products were developed with chestnut (Castanea sativa Mill.), using rice or chestnut koji as source of glycolytic enzymes. The analysis of the amazakes evolution showed improvements in chestnuts physicochemical characteristics. The fermented products presented higher values of soluble protein, sugars, starches, antioxidant capacity, and similar values of ascorbic acid for chestnut koji amazake. The adhesiveness increased, which is related to the enhanced concentrations of sugars and starches. The evolution into less structured products was observed in the firmness followed by a consistent decrease of the viscoelastic moduli. The developed chestnut amazakes can represent a suitable alternative to traditional amazake, creating an opportunity for valorisation of chestnut industrial by-products, as new, tasty, and nutritive fermented products with potential functional characteristics.

Improving nutritional quality of unripe tomato through fermentation by a consortium of yeast and lactic acid bacteria.

BACKGROUND: Portugal is one of the main producers of industrial tomato and tomato paste, an important intermediate ingredient used in many added-value foods. The tomato processing industry rigorously selects the fruits by colour during mechanical harvest, picking only completely ripe fruits to produce high quality tomato paste. The latest available data shows that about 1.12 × 108 kg yr-1 of non-red/not-ripe tomatoes are left in the field, representing a major side product/field residue with great impact on the environment and for tomato producers. RESULTS: The aim of the work was to use fermentation by a consortium of yeast and lactic acid bacteria to improve the nutritional quality of unripe tomato paste. A consortium of Lactobacillus plantarum, Leuconostoc mesenteroides and Kluyveromyces marxianus was selected, producing an acidic paste with olive-like flavours after 4 days of fermentation. Nutritional characterization revealed a significant improvement (P < 0.05) in the content of ascorbic acid and antioxidant potential. In addition, ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis showed that the fermented green tomato paste content in glycoalkaloid α-tomatine represents no hazard to the consumer. CONCLUSION: Therefore, the obtained fermented green tomato paste can be further used to produce new food products, such as salad dressings and sauces. © 2021 Society of Chemical Industry.