Browsing by Author "Cunha, L.M."
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- Impact of microalgae incorporation on sensory profile and consumer’s expectations of bread and cheesePublication . Ramos, R.M.; Barbosa, B.; Baião, L.; Lima, R.C.; Rocha, C.; Hernandéz, H.; Mahmoud, N.; Tavares, S.; Carvalho, C.C.C.R.; Nunes, M.C.; Raymundo, A.; Anjos, O.; Cunha, L.M.Microalgae are a promising future food source with their rich nutrient content and potential to contribute to a carbonneutral economy. However, incorporating microalgae into food formulations presents sensory challenges, particularly in terms of colour and distinct {sh-like aromas. In the YUM ALGAE project, this study successfully evaluated the impact of microalgae incorporation in two distinct food matrices – bread and camembert-like cheese. Four loaf bread samples and cheeses were assessed, incorporating chlorella (Chlorella vulgaris) or spirulina (Arthrospira platensis), both raw and with enzymatic treatment. A panel of 65 naïve tasters (aged between 20-59 years) was {rst invited to evaluate all the products’ expectations on a 9-point hedonic scale, visualising half-loafs and half-cheeses on a simulated store shelf. Then, at the sensory booth, participants were instructed to evaluate the samples’ appearance and odour, rating their overall acceptance and indicating the aspects they valued most and least when presented sequentially with a slice of each product. Simultaneously, using a Rate-All-That-Apply (RATA) ballot for appearance (no. of attributes: bread-11 and cheeses-8) and odour (no. of attributes: bread-10 and cheeses-8), a trained panel (n=10) evaluated each of the samples. The attributes were pre-de{ned based on the team experience, a literature review, and a pilot test with dried biomass from microalgae. Based on the naïve tasters' evaluation, all the samples had a high mean acceptance score (>6.0). No signi{cant differences were found between samples with raw microalgae incorporation and those treated with enzymes, except for cheese with chlorella, where the sample with raw chlorella had a higher value (p=0.02). Regarding the sensory pro{le, the sea-like odour intensi{es, and the cheese/bread odour decreases for the samples with enzymatic treatment. This research highlights the success of sensory research in the development of new alternative proteins, instilling con{dence in the potential to overcome the associated sensory barriers.
- Insect-based chitin and chitosan from whole body sources and rearing by-products: Extraction, physicochemical, structural and bioactivity characterisationPublication . Navarro, P.; Ribeiro, J.C.; Luís, Â.; Domingues, F.; Anjos, O.; Cunha, L.M.Fractionation of edible insects and their rearing by-products can lead to expanded industrial applications and extraction of value-added products. The main goal of this study was to extract chitin and synthesise chitosan from three different insect sources ‒ Tenebrio molitor larvae, adult Acheta domesticus and A. domesticus rearing by-products (legs and wings). Furthermore, the physicochemical, structural, and bioactive properties of insect-derived chitin and chitosan were characterised and compared to commercial crustacean-based samples. Chitin was isolated from defatted sources through chemical hydrolysis followed by decolourisation and was deacetylated with a strong alkaline solution to synthesise chitosan. Notably, A. domesticus rearing by-products yielded the highest chitin and chitosan content. Chitin and chitosan derived from insects exhibited physicochemical and structural characteristics consistent with the α-polymorphic form, similar to the commercial samples. Differences were found in surface morphology, with insect-derived samples presenting large and irregular flakes and porosity, while the crustacean-derived samples presented irregularly arranged fibres and a more regular and smoother surface. As for antioxidant activity, although all chitosan samples demonstrated poor DPPH radical scavenging activity, this study showed for the first time that insect-derived chitosan presents lipid peroxidation inhibition ability. All chitosan samples presented antimicrobial activity against different pathogenic bacteria, with K. pneumoniae being the most susceptible strain. Nevertheless, there is potential for enhancement of the biological properties through modifications on the molecular weight and deacetylation degree. This research introduces the potential of cricket-rearing by-products as sustainable sources of chitosan with functional bioactive properties.