A Dual Sensor for Biogenic Amines and Oxygen Based on Genipin Immobilized in Edible Calcium Alginate Gel Beads

2020 ◽  
Author(s):  
Ian Mallov ◽  
Fiona Jeeva ◽  
Chris Caputo
Keyword(s):  
Biogenic Amines ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Colorimetric Sensing ◽  
Naturally Occurring ◽  
Gel Beads ◽  
Dual Sensor ◽  
Calcium Alginate Gel ◽  
Toxic Food

Food is often wasted due to real or perceived concerns about preservation and shelf life. Thus, precise, accurate and consumer-friendly methods of indicating whether food is safe for consumers are drawing great interest. The colorimetric sensing of biogenic amines released as food degrades is a potential way of determining the quality of the food. Herein, we report the use of genipin, a naturally occurring iridoid, as a dual colorimetric sensor for both oxygen and biogenic amines. Immobilization of genipin in edible calcium alginate beads demonstrates that it is a capable sensor for amine vapors and can be immobilized in a non-toxic, food-friendly matrix.

scholarly journals A Dual Sensor for Biogenic Amines and Oxygen Based on Genipin Immobilized in Edible Calcium Alginate Gel Beads

2020 ◽  
Author(s):  
Ian Mallov ◽  
Fiona Jeeva ◽  
Chris Caputo
Keyword(s):  
Biogenic Amines ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Colorimetric Sensing ◽  
Naturally Occurring ◽  
Gel Beads ◽  
Dual Sensor ◽  
Calcium Alginate Gel ◽  
Toxic Food

Food is often wasted due to real or perceived concerns about preservation and shelf life. Thus, precise, accurate and consumer-friendly methods of indicating whether food is safe for consumers are drawing great interest. The colorimetric sensing of biogenic amines released as food degrades is a potential way of determining the quality of the food. Herein, we report the use of genipin, a naturally occurring iridoid, as a dual colorimetric sensor for both oxygen and biogenic amines. Immobilization of genipin in edible calcium alginate beads demonstrates that it is a capable sensor for amine vapors and can be immobilized in a non-toxic, food-friendly matrix.

Nitrification and Autotrophic Denitrification in Calcium Alginate Beads

1987 ◽  
Vol 19 (1-2) ◽  
pp. 175-182 ◽  
Author(s):  
Z. Lewandowski ◽  
R. Bakke ◽  
W. G. Characklis
Keyword(s):  
Calcium Carbonate ◽  
Calcium Ions ◽  
Continuous Flow ◽  
Calcium Alginate ◽  
Microbial Respiration ◽  
Flow System ◽  
Alginate Beads ◽  
Alginate Gel ◽  
Gel Beads ◽  
Calcium Alginate Gel

Immobilization of nitrifiers and autotrophic denitrifiers (Thiobacillus denitrificans) within calcium alginate gel was demonstrated. Calcium carbonate reagent was immobilized along with bacteria as the stabilizing agent. Protons released as a result of microbial respiration reacted with calcium carbonate producing calcium ions which internally stabilized the calcium alginate gel. The microbially active gel beads were mechanically stable and active for three months in a continuous flow system without addition of calcium.

Viability and delivery of immobilised Lactobacillus reuteri DPC16 within calcium alginate gel systems during sequential passage through simulated gastrointestinal fluids

2011 ◽  
Vol 2 (2) ◽  
pp. 129-138 ◽  
Author(s):  
Q. Zhao ◽  
S. Lee ◽  
A. Mutukumira ◽  
I. Maddox ◽  
Q. Shu
Keyword(s):  
Calcium Alginate ◽  
Lactobacillus Reuteri ◽  
Skim Milk ◽  
Alginate Beads ◽  
Simulated Gastric Fluid ◽  
Gi Tract ◽  
Calcium Alginate Beads ◽  
Alginate Gel ◽  
Alginate Concentration ◽  
Calcium Alginate Gel

The objective of the study was to design and produce calcium alginate beads that can deliver immobilised Lactobacillus reuteri DPC16 to a target site of the colon in the gastrointestinal (GI) tract. In this study, several factors that might affect the effectiveness of calcium alginate gel beads entrapping L. reuteri DPC16 cells were investigated. An in vitro GI tract model was used to simulate the pH variation and the existence of enzymes. Firstly, by varying the concentration of alginate at a constant concentration of CaCl2 the survival of immobilised DPC16 cells in simulated gastric fluid (SGF) was observed; secondly, the physical stability of calcium alginate beads containing skim milk during sequential incubation in the GI fluids was observed using optimal concentrations of alginate; finally, the survival of DPC16 cells immobilised within alginate beads containing skim milk were compared when the beads were incubated for different times during sequential exposure to the simulated fluids. The results demonstrated that non-encapsulated DPC16 cells were sensitive to an acidic environment, and no viable cells were detected after 90 min exposure in SGF (pH 1.2). With the protection of calcium alginate gel, the survival rate of immobilised DPC16 cells was slightly improved. An alginate concentration of 4% (w/v) was the most effective of those tested, but due to the irregular shape it formed, an alginate concentration of 3% (w/v) was used in further investigations. When skim milk (8% (w/v)) was added to the alginate solution, the cell survival was improved markedly. The optimal concentration of calcium chloride was 0.3 M, because the beads maintained their integrity in SGF and simulated intestinal fluid while disintegrating in simulated colonic fluid. The beads made from 3% alginate, 8% skim milk and 0.3 M CaCl2 proved to be an effective delivery and release system for DPC16 cells.

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