Edible-algae base composite film containing gelatin for food packaging from macroalgae, Gracilaroid (Gracilaria fisheri).

BACKGROUND: Conventional petroleum-based packaging films cause severe environmental problems. In this work bio-edible film as a safe to replace petroleum-based polymers was introduced. A food application for edible sachets and a composite edible film (EF) from marine algae, Gracilaria fisheri (GF) extract were proposed. RESULTS: Carbohydrates were the most prevalent component in fresh GF fronds. Under neutral conditions at 90 °C for 40 min, the extract's structure was determined by FTIR to be a carrageenan-like polysaccharide. Glycerol was the best plasticizer for EF formation since it had the highest tensile strength (TS). The integration of gelatin into the algal composite film with gelatin (CFG) was validated by significant. The best casting temperatures for 2 h were 70 and 100 °C among the four tested temperatures (25, 60, 70, and 100 °C). Temperatures did not result in significant (p ≤ 0.05) differences in any character (color values, TS, water vapor permeability, oxygen transmission, thickness, and water activity), except elongation at break. Visually, the CFG had a slightly yellow appearance. The best-to-worst order of film stability in the three tested solvents was oil, distilled water (DW), and ethanol. Its stability in ethanol (0-100%), temperature of DW (30-100 °C), and pH (3-7 in DW) demonstrated inverse variations with the concentration or different conditions, except for pH 8-10 in DW. All treatments were significantly (p ≤ 0.05) different. CONCLUSION: The novel material made from polysaccharides from algae, G. fisheri, was used to improve EF. The edible sachet application was plausible from the EF. This article is protected by copyright. All rights reserved.

HACCP plan for microbiological hazards associated with fermented crab, Episesarma mederi H. Milne Edwards 1853.

AIMS: To develop a model HACCP plan related to the microbiological hazards for the traditional fermented crab. METHODS AND RESULTS: The microbiological and chemical characteristics of commercial products were surveyed. Microbiological hazard analysis was performed for raw materials and during processing. Critical control points (CCPs) were determined using a decision tree, with CCP1 as saturated salt preparation and CCP2 as fermentation. The critical limit (CL) of CCP1 was at 100°C for 20 min applied to brining and of CCP2 was at 25% NaCl for the brine applied to fermented crab. Isolated microbial hazards and type strains were used for the validation of the CLs. Monitoring and verification of the proposed HACCP plan were carried out, and an effective HACCP plan was established. CONCLUSIONS: The HACCP plan promoted the safe consumption of fermented crab with the provided CCPs at the saturated salt preparation and fermentation steps. The effective CLs to ensure microbiological hazards as safe at the CCPs provide the best support for an effective plan. The hazards were reduced significantly after the HACCP plan had been applied.

Rice flour powder carrying mixed starter culture of Lactiplantibacillus plantarum KU-LM173 and Pediococcus acidilactici KU-LM145 for fermented mussel, Perna viridis Linnaeus 1758.

AIMS: To develop a dried rice flour powder (DP) formulation to contain a lactic acid bacterial starter culture for fermenting mussel meat (FM). METHODS AND RESULTS: Lactiplantibacillus plantarum KU-LM173 (LP), Enterococcus hirae KU-LM174 and Pediococcus acidilactici KU-LM145 (PA) were selected from commercial FMs and identified to have high acid and protease production. Mixed culture between LP, for high acid production, and PA, for the flavour, was the best for DP and had greater organoleptic properties than a single starter fermentation. The best ratio of DP for production was 1% of the mussel weight, while the highest numeric scoring of the organoleptic test between 3% and 6%. The starter culture fermentation accelerated over the natural (wild) fermentation and ended at day 3. The shelf life of the product was at least 30 days at 30-35°C with no pathogens detected. The shelf life of DP at 4°C was 10 weeks. CONCLUSIONS: DP with the best strains and long shelf life promoted safety of FM and reduced the processing time. High consumer acceptance, protease and acid production and flavour were unique product characteristics. SIGNIFICANCE AND IMPACT OF STUDY: Accelerated commercial FMs with effective DP formulation for the industrial sector may be plausible.

Hydroperoxy-arachidonic acid mediated n-hexanal and (Z)-3- and (E)-2-nonenal formation in Laminaria angustata.

In higher plants, C6 and C9 aldehydes are formed from C18 fatty acids, such as linoleic or linolenic acid, through formation of 13- and 9-hydroperoxides, followed by their stereospecific cleavage by fatty acid hydroperoxide lyases (HPL). Some marine algae can also form C6 and C9 aldehydes, but their precise biosynthetic pathway has not been elucidated fully. In this study, we show that Laminaria angustata, a brown alga, formed C6 and C9 aldehydes enzymatically. The alga forms C9 aldehydes exclusively from the C20 fatty acid, arachidonic acid, while C6 aldehydes are derived either from C18 or from C20 fatty acid. The intermediates in the biosynthetic pathway were trapped by using a glutathione/glutathione peroxidase system, and subjected to structural analyses. Formation of (S)-12-, and (S)-15-hydroperoxy arachidonic acids [12(S)HPETE and 15(S)HPETE] from arachidonic acid was confirmed by chiral HPLC analyses. These account respectively for C9 aldehyde and C6 aldehyde formation, respectively. The HPL that catalyzes formation of C9 aldehydes from 12(S)HPETE seems highly specific for hydroperoxides of C20 fatty acids.

C6-aldehyde formation by fatty acid hydroperoxide lyase in the brown alga Laminaria angustata.

Some marine algae can form volatile aldehydes such as n-hexanal, hexenals, and nonenals. In higher plants it is well established that these short-chain aldehydes are formed from C18 fatty acids via actions of lipoxygenase and fatty acid hydroperoxide lyase, however, the biosynthetic pathway in marine algae has not been fully established yet. A brown alga, Laminaria angustata, forms relatively higher amounts of C6- and C9-aldehydes. When linoleic acid was added to a homogenate prepared from the fronds of this algae, formation of n-hexanal was observed. When glutathione peroxidase was added to the reaction mixture concomitant with glutathione, the formation of n-hexanal from linoleic acid was inhibited, and oxygenated fatty acids accumulated. By chemical analyses one of the major oxygenated fatty acids was shown to be (S)-13-hydroxy-(Z, E)-9, 11-octadecadienoic acid. Therefore, it is assumed that n-hexanal is formed from linoleic acid via a sequential action of lipoxygenase and fatty acid hydroperoxide lyase (HPL), by an almost similar pathway as the counterpart found in higher plants HPL partially purified from the fronds has a rather strict substrate specificity, and only 13-hydroperoxide of linoleic acid, and 15-hydroperoxide of arachidonic acid are the essentially suitable substrates for the enzyme. By surveying various species of marine algae including Phaeophyta, Rhodophyta and Chlorophyta it was shown that almost all the marine algae have HPL activity. Thus, a wide distribution of the enzyme is expected.