Melanosis is a bio‐chemical reaction that reduces the acceptability of refrigerated shrimps. The current research aims to produce and characterize chitosan‐based coatings added of propolis extract (PE), as well as to investigate the potential application of these materials to control the melanosis of refrigerated shrimps during storage (9 days). Shrimps are coated with chitosan solutions content different PE concentrations (0%, 5%, 10%, and 20%). Uncoated shrimps and shrimps coated with sodium metabisulfite are also investigated. The incorporation of PE modifies the crystalline structure of chitosan, reducing the water contact angle, and thermal stability of films. Shrimps coated with chitosan‐based solutions containing 20% of PE display lower dark points in the cephalothorax and joints region, as well as better weight retention during storage. These results suggest that chitosan‐based coatings containing PE can be an eco‐friendly alternative to substitute sodium metabisulfite in refrigerated shrimps.

Microbial volatile organic compounds (MVOCs) are present in several production processes in biotechnology. In this study it is evaluated the viability of use of a method involving solidphase microextraction (SPME), in vivo SPME, in the extraction of MVOCs, associated with the pigment production process by the Monascus fungus. PDMS/Car/DVB (50/30 μm) fiber in the headspace mode (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were used to fermentation broth study. Seventeen compounds were found associated with the presence of the fungus, being the main ones ethanol, 2-methyl-propanol, 3-methyl-butanol, 2-methyl-butanol and 2-phenyl-ethanol. These compounds have maximum concentration of 313.87, 5.51, 2.37, 0.95 and 0.70 mg L −1 . The values of biomass and red pigment found for fermentation for ten days were 4.03 ± 0.21 g L −1 and 3.96 ± 0.17 (UA 480 ). Regular MVOC productions were observed in this study, which were useful in the prediction and control of fermentation by Monascus fungus.

RESUMO-o objetivo deste trabalho foi avaliar a produção de pigmentos vermelhos por Monascus ruber (CCT 3802) em meio de cultivo submerso contendo caldo de cana diluído (aproximadamente 3ºBrix) e bagaço de cana (10 g.L-1) desidratado por liofilização como fontes de carbono. Os ensaios foram realizados em frascos Erlenmeyer contendo 250 mL de volume de meio, a 30 ºC de temperatura, pH inicial 5,5, 150 rpm de frequência de agitação. A fonte de nitrogênio foi a glicina, responsável pela formação de complexos vermelhos hidrossolúveis. Os resultados demonstraram que esta linhagem de fungo produz concentrações elevadas de pigmento vermelho (21,8 UAbs509), sugerindo que o fungo Monascus utiliza além da glicose como substrato, outros carboidratos oriundos da hidrólise da celulose. Além disso, há poucos relatos bibliográficos sobre a fermentação submersa em caldo-de-cana o que justifica este tipo de estudo. Palavra chave: biopigmento, Monascus ruber, cana de açúcar.