Evaluation of CO2 Biofixation and Biodiesel Production by Spirulina (Arthospira) Cultivated In Air-Lift Photobioreactor

ABSTRACT Spirulina is a microalgal genre that has the capacity to produce various bioproducts with applications in several areas including the energy sector. The study aimed to assess the ability of CO2 biofixation, biodiesel and other biocompounds production by Spirulina sp LEB 18 cultured in air-lift photobioreactor. The microalgae presented a rich macronutrient composition: protein (47.3%), carbohydrates (13.4%) and a high lipid content (32.7%) in a media with nitrogen reduction, CO2 using air-lift photobiorector. Furthermore, 160 mg.L.d-1 of CO2 was biofixed, generating a maximum biomass yield of 0.02 g.L.d-1. The lipids evaluated for biodiesel production presented a theoretical yield of 19.8% for in situ transesterification and 47.9% for conventional transesterification. The microalgal biomass has potential for producing biodiesel that can be applied instead or in mixture with traditional diesel fuel. The study of obtaining energy associated with the production of other high value-added biocompounds from the microalgal biomass is of high importance because in this way, the viability of biofuel production by this microorganism can be increased.

Sensory profile of sheep cheeses during a six-month storage period as evaluated by consumers.

Over the past decade, the use of check-all-that-apply questions has become an easier and faster alternative to traditional sensory profiles using trained assessors, allowing the characterisation of a product by consumers. In this study, 65 consumers evaluated the acceptability of six artisan Uruguayan sheep cheese samples during a six-month storage period, providing a descriptive profile using a check-all-that-apply questionnaire consisting of 32 sensory and non-sensory terms. Although the acceptability of five of the six samples was not modified during storage, the consumers were able to perceive changes in the texture and flavour of products, providing a sensory profile of the cheeses. The categories s trange flavour, animal odour, strange odour, bitter and acidic were associated with negative terms such as bad quality and unpleasant flavour, whereas salty and tasty appeared to be related to positive terms including good quality, pleasant flavour and delicious. Therefore, for the Uruguayan consumer, preference for this type of product appears to be mainly conditioned by the flavour perceived in these cheeses, rather than their texture attributes.