LATVIA UNIVERSITY OF AGRICULTURE - Latvijas ...

Maija Kronberga, Daina KarklinaCHEMICAL COMPOSITION OF NEW TYPE AGARJELLIES WITH JERUSALEM ARTICHOKE SYRUPFigure 5. Changes in hardness of experimental jelly samples with Jerusalem artichoke syrup.Figure 6. Correlation between soluble dry matter and hardness of experimental jellysamples with Jerusalem artichoke syrup.Replacement of sucrose in jellies causestechnological problems since sucrose in soluble drymatter is essential to form the gels structure. Theamount of sucrose in experimental samples decreasedby increasing the amount of Jerusalem artichokesyrup. When the Jerusalem artichoke syrup was addedto the jelly samples, the level of acidity increased. Thedifferences in acidity value between control sampleand experimental samples could be explained by theincreased syrup concentration in samples. Such anincrease can be explained by the organic acids presentin JAS which has рН=4.7 and an increased proportionof liquid, which partially diluted the jelly samples. Inthe samples with 60-100% sugar substitution it is seenthat jelly hardness decreased due to increased acidityand decreased dry matter.Colour is a very important quality indicator, wherelight colour has been demonstrated to be very attractivefor consumers. Food colour has a significant impactby being one of the major factors used by consumersto take the purchasing decision. Results of L* value ofexperimental jellies are presented in Figure 7.A higher L* value of experimental samples withcontrol sample and sample by 20% JAS comparedwith other samples. The addition of increasingamounts of JAS in result gave an undesirable colourfor jelly. By increasing the JAS ratio in experimentaljelly, the mixture obtained a darker colour since JAS isdarker in colour. The lightness L* of jelly decreased inall samples. At significance level 0.05, the brightnesshad no significant differences between the samplesJAS40, JAS 60, JAS 80 and JAS 100, but there weresignificant difference in the samples JAS 20 andControl. The blue-yellow chromatically (b*) valueswere significantly higher in control sample, but in allsamples, prepared with JAS, it decreased from 18.12to 4.2. Changes in a* values in all prepared samplesincreased from 2.55 to 9.42.The obtained results showed, that the added amountof JAS in result gave darker colour for experimentaljellies. We have to think regarding to colour changes,if we would like to use JAS for production jellies.It is very important to consider that the quality of ajelly strongly depends on sensory perceptions of theResearch for Rural Development 2012121