The main component of konjac powder is glucomannan (KGM), and its chemical structure is composed of D-glucose and D-mannose residues with a molecular ratio of about 15:23 through β-1,4 glycoside bonds to polymerize into a main chain of polymer heteropolysaccharides with a molecular weight of 200,000 to 2 million daltons. Konjac powder can be swelled in water to form a high viscosity sol, which can react with k-type carrageenan to form a highly elastic thermal reversible gel.
The compound use of carrageenan and konjac powder has been used in the industry for many years, such as in fish products, meat sausage products, jelly gel products and other aspects have been widely used.
<h1 class="pgc-h-arrow-right" data-track="5" >01 Effect of gel strength of carrageenan and konjac powder compound on jelly quality under different ratios</h1>
When the total concentration remains unchanged after the compound, carrageenan and konjac powder produce synergistic effects, forming a stable gel, so that the gel strength is improved and the taste is delicately lubricated. In jelly making, carrageenan is 0.3%, konjac powder 0.4%, and KCl 0.3%, and the taste is the best.
<h1 class="pgc-h-arrow-right" data-track="47" >02KCl vs. gel strength</h1>
With the increase of KCl addition, the gel strength of carrageenan increases, but with the increase of KCl, the brittleness, water evolution and shrinkage of the gel will become larger. The gel strength after the addition of KCl is larger than that of no KCl at low concentrations, and gradually becomes consistent at high concentrations, which is because the amount of K+ is certain, and the binding and weakening of molecular repulsion are certain, and do not increase with the increase of carrageenan concentration.
<h1 class="pgc-h-arrow-right" data-track="48" >03 The relationship between konjac powder and water retention</h1>
With the reduction of konjac powder, the jelly water evolution phenomenon is aggravated, and the appropriate increase in the proportion of konjac powder in the jelly can improve the dehydration shrinkage rate of the jelly, effectively overcome the serious shortcomings of the carrageenan dehydration shrinkage phenomenon, and also make the jelly produced moderate hardness, good toughness and elasticity, and chewing feeling.
<h1 class="pgc-h-arrow-right" data-track="49" >04pH vs. gel strength</h1>
Compound glue in the pH = 3.5 below the heat can only form a very weak gel, after the pH of 5 ~ 7 heating, the gel is basically stable in a relatively high numerical range; pH = 7.5 or more heating, the strength of the compound glue is reduced. It may be that konjac powder is hydrolyzed in an alkaline environment and affects the final gel strength.
<h1 class="pgc-h-arrow-right" data-track="50" >05 Effect of acid addition on gel strength at different temperatures</h1>
The higher the temperature when acid is added, the weaker the gel is. This phenomenon is consistent with the Arenius formula, and the reaction rate of acid-catalyzed degradation of carrageenan increases with increasing temperature. The strength value is stable when acid is added at 80~60 °C, and the strength of the gel decreases when acid is added at 60~50 °C. This may be due to the fact that at lower temperatures, when it approaches the gel temperature range, the double helix tends to occur, and the addition of H+ greatly interferes with the ability of K+ to form H bonds with the negative charge of carrageenan sulfate, and the three-dimensional network formed is more relaxed, so the intensity measured macroscopically is lower.
<h1 class="pgc-h-arrow-right" data-track="52" >06 Effects of different acid additions on gel strength</h1>
As the amount of acid added increases, the gel strength decreases. The compound glue is added at about 0.15% acid, and the gel strength decreases slowly.
<h1 class="pgc-h-arrow-right" data-track="53" > in summary</h1>
(1) When the total glue concentration is unchanged, carrageenan is compounded with konjac powder and KCl to produce synergistic effect, and the taste and appearance of jelly are obviously different under different proportions. Practice has proved that 0.3% carrageenan, 0.4% konjac powder and 0.3% KCl compound effect is better.
(2) The gel strength of carrageenan depends on the neatness of the molecular chains, but an increase in the amount of addition can increase the strength. A small amount of carrageenan is compounded with konjac powder to obtain a high-strength gel.
(3) The more citric acid is added to the colloidal solution, the lower the strength after cooling, and the higher the intensity of the acid temperature, the more significant the decrease. However, adding acid at too low a temperature will also interfere with the formation of the gel, so the most appropriate acidion temperature is 80 ~ 60 ° C.
(4) The compounding of carrageenan and konjac powder can greatly reduce the dehydration shrinkage rate of jelly, that is, the phenomenon of water evolution can be improved. At the same time, it shows that its compounding with konjac powder is feasible, which expands the scope of konjac powder as a gel in food applications.
(5) The carrageenan solution system is heated at different pH, the pH is reduced and the gel strength is reduced, and the gel cannot be formed below pH = 3.5. The gel that has been formed is stable even at a high acid such as pH = 3.5. The results observed in the compound glue system are similar to carrageenan, but in an alkaline environment, the strength is reduced, while carrageenan is still stable at about pH = 9.
bibliography:
"Research on the Production of Jelly Powder by Compounding Carrageenan and Konjac Powder"
【Copyright Notice】
Some of the pictures are reproduced on the Internet, the copyright belongs to the original author, only for learning and reference, prohibited for commercial use, if you have any objections, please contact 0717-6850363.