Suchergebnisse

A functional microemulsified concentrate was obtained from an industrial shrimp cooking effluent by using a centrifugal separator, resulting in a new effluent with only 5% of dry matter. The shrimp concentrate (C) showed valuable properties for use as a bioactive ingredient, being rich in lipids (~16%) and proteins (~11% w/w), and exhibiting antioxidant (radical scavenging capacity and reducing power) and antimicrobial properties. Chitosan–gelatin (ChG) biocomposites with and without the shrimp concentrate were prepared and characterized. The incorporation of C provided film-forming dispersions (S-ChGC) and dried films (F-ChGC) with increased antioxidant and antimicrobial activity. The film microstructure changed with the incorporation of the concentrate, which caused an evident plasticizing effect and reduced the tensile strength. The resulting biocomposites containing the shrimp cooking concentrate showed great potential for use in food applications (as food preservation or food design), medical devices or for cosmetic purposes, as wound dressing or film matrix for application on mucous membranes and epithelia with different functionalities. ; This research was financed by: (i) the Spanish Ministry of Economy and Competitiveness through project AGL2011-27607, AGL2014-52825-R and project AGL2017-84161-C2 and (ii) the Spanish National Research Council (CSIC) through project 201370E036. M. Arancibia was funded by a SENESCYT Scholarship provided by the Ecuadorian government. ; Peer Reviewed

An active shrimp concentrate (SC), obtained from Litopenaeus vannamei cooking juice, was incorporated into a chitosan-gelatin matrix to develop edible packaging covers (coating and film). Both types of packaging, which showed antimicrobial activity against some fish spoilers and pathogenic organisms, were applied to preserve fish sausages during chilled storage. The storage trial showed that the coating increased the lag phase of total viable microorganisms and enterobacteria to 15 and 10 days, respectively, while the film drastically inhibited growth of these groups. No presence of Staphylococcus aureus or lactic acid bacteria was detected in any batches during storage. Total volatile bases and pH values also decreased during storage, the decrease being more pronounced in the film. With regard to physical-chemical properties, the coated sausages exhibited values for moisture, water holding capacity, and shear strength similar to those of the control sausages until about day 25. The coating was imperceptible and could be a promising way of improving the quality of sausages during storage since it delayed microbial growth. The sausages wrapped in the film showed a drop in pH and moisture, as well as texture hardening, and were described as resembling a pickled product. The sausages were stable for at least 42 days, which represents a shelf life increase of at least this time with respect to the control sausages (in commercial plastic casings). The coating and the film had different effects on the physicochemical and microbiological properties of the fish sausage, and therefore on the stability of the product. In addition, the film triggered modifications in the product that resulted in a product different from the original, offering an attractive alternative with regard to product design. ; This research was financed by the Spanish Ministry of Economy and Competitiveness through projects AGL2011-27607, 201370E036, and AGL2014-528225. Ecuadorian government by scholarship SENESCYT. ; Peer Reviewed

7 páginas, 3 figuras, 2 tablas ; A concentration-response bioassay against the Mediterranean fruit fly, Ceratitits capitata, was performed to evaluate the insecticidal activity of biodegradable films containing clove (Eugenia caryophyllata, Myrtaceae) or citronella (Cymbopogon nardus, Poaceae) oils. We recorded the time of knock down flies after the exposure to soy protein-lignin films incorporated with 3% food grade clove or citronella essential oils, or control films without bioactive. The vapors of clove released from the film containing 3% essential oil were efficient to trigger the tumbling of the flies (40% after 4 h exposition) and after 20 h 90% of the flies died. However, films containing citronella essential oil had poor insecticidal activity. Citronella oil have a much higher insecticidal activity in a pure form, but probably one or both of their main bioactive compounds (citronellal and geraniol) were poorly released from the films. In this work, for the first time, a novel packaging system controlling the release of essential oil of clove with good insecticidal activity against Ceratitits capitata was achieved, that can be used to improve quality of fruit and for food products. ; Thank for the financial support to SENESCYT Scholarship of the Ecuadorian government of M. Arancibia and CYTED (action 309AC0382) Agrobioenvase ; Peer reviewed

Eight seafood protein hydrolysates (SPHs) obtained from squid, shrimp and fish gelatin were incorporated as substitutes of peptones in culture media in order to evaluate its effect on survival and metabolic activity (lactic acid, acetic acid and bacteriocins production) of Enterococcus faecalis DM19. The substitution of commercial peptones in culture media by either a shrimp hydrolysate prepared with Protamex, or by squid protein hydrolysates prepared with Esperase or Alkaline protease, stimulated E. faecalis DM19 growth up to 16%. The incorporation of SPHs, mainly from shrimp, in the culture media significantly increased production of lactic and acetic acids in more than 60%. Furthermore, the media containing SPHs stimulated antimicrobial activity by E. faecalis DM19. The inhibitory activity was observed against both Gram-positive and Gram-negative microorganisms, but it was remarkably observed against Listeria monocytogenes. SPHs incorporated in culture media render properties of bio-technological interest, which, together with their low price, make them suitable for industrial use. ; This research was financed by the Spanish Ministry of Economy and Competitiveness (projects AGL2011-27607, AGL2014-52825-R). Author M. Djellouli is funded by The National Centre of Biotechnology Research (CHER-Stage 06-2013) (CNRBt) of Algeria and ENP (Exceptional National Program) Scholarship provided by the Ministry of Higher Education and Scientific Research of Algeria (099/PNE/ENS./ESPAGNE/2015-2016). Author M. Arancibia is funded by a SENESCYT Scholarship (20100338) provided by the Ecuadorian government. ; Peer Reviewed