PARAMETER KINETIKA INAKTIVASI TERMAL DAN ISOLASI Staphylococcus aureus PADA MINUMAN DARI GEL CINCAU HIJAU DAN ROSELA [Thermal Inactivation Kinetics Parameter and Isolation of Staphylococcus aureus on Drink from Green Grass Jelly and Roselle]

• Main Authors: Eko Hari Purnomo, Puspo Edi Giriwono, Dias Indrasti, Antung Sima Firlieyanti, Andini Giwang Kinasih
• Format: Article
• Language: English
• Published: Bogor Agricultural University; Indonesian Food Technologist Association (IAFT) 2015-07-01
• Series: Jurnal Teknologi dan Industri Pangan
• Subjects: D value; green grass jelly; roselle; Staphylococcus aureus; z value
• Online Access: http://journal.ipb.ac.id/index.php/jtip/article/view/10711
• ISSN: 1979-7788; 2087-751X

<p class="Paragraf"><em>Information </em><em>about</em><em> heat resistance (D and z values) of target bacteria </em><em>is</em><em> </em><em>needed</em><em> for the thermal process design o</em><em>n drink from</em><em> Green Grass Jelly (Premna oblongifolia Merr.) and Roselle (Hibiscus sabdariffa L.)</em><em>, so it can</em><em> guarantee quality</em><em> and safety</em><em> of the product. The </em><em>objectives</em><em> of this research </em><em>were</em><em> to isolate Staphylococcus aureus from commercial</em><em> </em><em>green</em><em> grass jelly</em><em> and to determine the D and z values of Staphylococcus aureus</em><em> (from commercial product and standard clinical isolate ATCC 25923) on </em><em>heating menstruum</em><em> of </em><em>green grass jelly and roselle. </em><em>Isolation of S. aureus was done by </em><em>inoculation</em><em> in </em><em>selective</em><em> medium, </em><em>D and z values of Staphylococcus aureus were assessed by heating at constant temperatures of 57, 53, 49, and 45°C during the time interval 2.5, 5, 10, and 15 minutes. </em><em>The</em><em> results show</em><em>ed</em><em> that one isolate (Isolate A) </em><em>gave</em><em> positive </em><em>response</em><em> of Staphylococcus aureus in</em><em> isolation tests</em><em> and ha</em><em>d</em><em> similar percentage with the reference culture of 41.8% using the API Staph Kit. Heat resistance of Staphylococcus aureus (represented as D value) isolated from green grass jelly at constant heating temperature of D₄₅, D₄₉, D₅₃ and D₅₇ </em><em>were</em><em> </em><em>32.3, 17.9, 4.6, and 1.5 </em><em>minutes. On the other hand, D value of isolates ATCC 25923 (standard clinical isolate) at constant heating temperature of D₄₅, D₄₉, D₅₃ and D₅₇</em><em>were</em><em> </em><em>18.5, 6.8, 2.9, and 1.4</em><em> minutes. </em><em>The z value of i</em><em>solates A</em><em> and ATCC 25923</em><em> </em><em>were</em><em> 8.8°C </em><em>and</em><em> 10.8°C. Smaller z value of isolate A show</em><em>ed</em><em> that pasteurization</em><em> process</em><em> can be accelerated and optimized with </em><em>increasing the</em><em> temperature </em><em>slightly but has the same lethality effect</em><em>. </em><em></em></p>