Status : Verified
| Personal Name | Zacarias, Angelica T. |
|---|---|
| Resource Title | Effect of pH on the physico-chemical sensory and antioxidant activity of Tiesa (Pouteria campechiana (HBK) Baehni) jam |
| Date Issued | 08 June 2016 |
| Abstract | The effect of pH on the physico-chemical, sensory and antioxidant activity of tiesa jams was investigated and evaluated. Tiesa jam samples with varying levels of pH (3.3, 4.0, 4.5, 5.0, 5.5) were analyzed for water activity (Aw), color, viscosity, DPPH-radical scavenging activity and consumer acceptance test. Aw of the jam samples were low, with a mean of 0.772, comparable to other fruit jams, indicating a sample relatively stable from spoilage. An overall decrease in color parameters were observed as a consequence of intense thermal processing with an average decrease of 36.07%, 33.72% and 24.08% in L*, a* and b* values, respectively from color parameters obtained from fresh tiesa flesh. Regression analysis on the effect of pH was only significant for L* value. Effect of pH on the viscosity of the jams were found to be negatively correlated with increasing pH levels resulting in lower viscosity measurements, due in large part, to the effect of pH on the gelling capacity of pectin. Viscosity measurements ranged from 24,950 cP to 43,246.67 cP and were comparable to viscosity of other fruit jams. A decreasing trend in the antioxidant activity of the jams was also observed with increasing pH, ranging from 25.16 to 35.17% inhibition. Sensory evaluation responses reveal that consumers prefer tiesa jam samples that have a darker yellow-orange color, higher levels of sweetness and sourness, less viscous and with a stronger aroma. Overall acceptability of tiesa jam with pH 5.5 were found to be statistically higher (P>0.05) than the rest of the samples with an average rating of 6.22 ("like slightly"). Tiesa jam with pH 5.5 also received statistically higher Hedonic ratings for other sensorial parameters, namely spreadability, sourness, sweetness and aroma. |
| Degree Course | Bachelor of Science in Food Technology |
| Language | English |
| Keyword | Jam--Philippines |
| Material Type | Thesis/Dissertation |
Preliminary Pages
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Category : P - Author wishes to publish the work personally.
Access Permission : Limited Access