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ABSTRAK pH, kadar air, hidroksimetilfurfural (HMF), kadar gula total, aktivitas antibakteri, dan antioksidan. Sampel madu diambil secara purposive sampling (sengaja) dari hutan lindung Kalung, Desa Namang, Kabupaten Bangka Tengah. Hasil penelitian menunjukkan bahwa karakteristik warna madu adalah L* 27,07+0,31; a*1,17 ± 0,15; b* 1,17 ± 0,12. Nilai pH 3,92 ± 0,01, kadar air 24,25 ± 1,49%, kadar HMF 0 mg/kg, kadar gula total 74,77 ± 0,15%. Madu ini memiliki aktivitas antioksidan rendah dengan nilai IC 50 sebesar 1,71 mg/mL dan memiliki sifat antibakteri terhadap Eschericia coli dan Staphylococcus aureus dengan diameter zona bening berturut turut sebesar 1,50 mm dan 2,25 mm. Kata kunciABSTRACT including colour, pH, water content, hidroksimetil-furaldehid (HMF), total sugars, antibacterial, and antioxidant activities. Honey was obtained from Kalung protected forest in Namang village, Central Bangka Regency. Results showed that the initial characteristics of honey were L* 27.07 ± 0.31; a* 1.17 ± 0.15; b* 1.17 ± 0.12. The pH value was 3.92 ± 0.01, water content 24.25 ± 1.49%, HMF 0 mg/kg, total sugars 74.77 ± 0.15%. This honey had low antioxidant activity at the IC 50 level of 1.71 mg/mL, and its clear zone diameters against both Eschericia coli and Staphylococcus aureus were 1.50 mm and 2.25 mm, respectively.

ABSTRAKPenelitian ini bertujuan untuk mengetahui karakteristik fisik dan kimia pati ganyong dan gadung sebelum dan setelah dimodifikasi dengan menggunakan metode ikatan silang (cross linking). Penelitian ini terdiri atas dua tahap. Tahap pertama adalah karakterisasi pati dari umbi ganyong dan umbi gadung. Tahap kedua pembuatan pati termodifikasi dari pati ganyong dan gadung melalui ikatan silang dengan menggunakan POCl 3 pada konsentrasi 0,04% (v/v); 0,08% (vv); dan 0,12% (v/v). Rancangan penelitian tahap pertama menggunakan tabulasi dan tahap kedua rancangan acak lengkap non faktorial dengan lima kali ulangan. Hasil penelitian menunjukkan bahwa kadar pati umbi ganyong sebesar 41,35% dan 38,80% untuk pati umbi gadung. Kadar amilosa pati ganyong 17,59% dan pati gadung 8,92%. Pati ganyong modifikasi mengandung fosfat sebesar 15,74 ppm sedangkan pati gadung 9,54 ppm. Ukuran granula pati ganyong berkisar 20-50 μm dan pati gadung 4,32-4,25 μm. Kadar pati dan amilosa umbi ganyong dan gadung setelah dimodifikasi mengalami penurunan secara signifikan dengan semakin tinggi konsentrasi POCl 3, sedangkan kadar fosfat, derajat substitusi, dan kadar HCN untuk pati gadung mengalami penurunan.Kata kunci: Fosfat, ganyong, gadung, ikatan silang, pati ABSTRACTThe research aimed at studying physical and chemical characteristics of Canna edulis Kerr and Dioscorea hispida Dennst unmodified and modified starch with cross-linking method. This research was divided into two stages. The first stage of the research was characterization of starch from Canna edulis Kerr and Dioscorea hispida Dennst and the second stage of the research was processing of modified starch from Canna edulis Kerr and Dioscorea hispida Dennst through cross-linking by using POCl 3 at the concentration of 0.04%(v/v), 0.08%(v/v), dan 0.12%(v/v). There was no specific research design for the first stage of the research. The collected data was tabulated. The research design for the second stage was non factorial completely randomized design with five replications. The results showed that C. edulis contained starch content (41.35%) and D. hispida (38.80%). C. edulis starch had amylose content (17.59%) and D. hispida starch 8.92%. The modification of C. edulis starch contained of phosphate (15.74 ppm) and D. hispida 9.54 ppm. The starch granule was found in C. edulis (20-50 μm) and starch granule was in D. hispida (4.23 to 4.52 μm). The physical and chemical characteristics of modified C. edulis and D. hispida starch were not similar to the unmodified starch. The amylose and starch contents in the modified starch was reduced, on the other hand, the phosphate content was increased, whereas the granule size was unchanged.Keywords: Canna edulis Kerr, cross-linking, Dioscorea hispida Dennst, phosphate, starch PENDAHULUANPati alami umumnya mempunyai struktur lemah, gel yang kohesif, suhu gelatinisasi tinggi, kemampuan membentuk gel tinggi pada dispersi pati, kemampuan menahan air rendah pada suhu rendah, ketahanan dipersi pati rendah terhadap asam, agitasi, dan pasta dengan k...

Application of supercritical carbon dioxide for processing of food products has an impact on microbial inactivation and food quality. This technique is used to preserve tempeh due to no heat involved. The quality of tempeh is highly influenced by mold growth because of its role in forming a compact texture, white color, and functional properties as well as consumer acceptance. This study aims to observe viability of molds and bacteria in tempeh after processed with supercritical CO2 and to determine the best processing conditions which can maintain mold growth and reduce the number of bacteria in tempeh. For that purpose, tempeh was treated using high pressure CO2 at 7.6 MPa (supercritical CO2) and at 6.3 MPa (sub/near supercritical CO2) with incubation period of 5, 10, 15, and 20 min. The best treatment obtained was used to process tempeh for storage study. The results showed that there was a significant interaction between pressure and incubation period for bacterial and mold viability at ρ>0.05. Reduction of bacteria and molds increased with longer incubation period. Molds were undetectable after treatment for 20 min with either supercritical CO2 or sub-supercritical, and bacteria significantly reduced up to 2.40 log CFU/g. On the other hand, sub-supercritical CO2 for 10 min was the best processing method because molds survived 4.3x104 CFU/gram after treatment and were able to grow during storage at 30°C, producing white mycelium as indicated by increasing the L⁎ color value and tempeh acceptability. The inactivation of mold was reversible causing it to grow back during storage under suitable conditions. Tempeh matrix composition can provide protection against the destructive effects of supercritical CO2. Gram-positive bacteria were more resistant than Gram-negative. In conclusion, sub-supercritical CO2 can act as a method of cold pasteurization of tempeh and can be used as an alternative method to preserve tempeh.

ABSTRAKPenelitian modifikasi pati ganyong melalui perlakuan heat-moisture-treatment (HMT) dan penambahan gum xanthan (GX) dilakukan untuk memperbaiki kelemahan pati ganyong alami sehingga menjadi luas aplikasinya dalam industri pangan terutama produk rerotian. Penelitian menggunakan rancangan acak kelompok faktorial dengan 3 perlakukan dan 3 ulangan. Perlakuan yang diberikan adalah waktu (8 dan 16 jam), suhu (80 °C dan 100 °C), kadar air 15 % dan konsentrasi gum xanthan (0, 0,5; 1; 1,5; 2 %). Data dianalisis dengan sidik ragam (ANOVA) pada α = 0,05, dilanjutkan dengan uji BNJ (α = 0,05). Parameter yang diamati swelling power (SP), indeks kelarutan dalam air (IKA), indeks absobsi air (IAA), derajat pengembangan (DP), dan densitas kamba (DK) pati ganyong termodifikasi. Hasil penelitian menunjukkan bahwa modifikasi pati ganyong dengan kombinasi perlakuan suhu dan waktu HMT serta konsentrasi GX menghasilkan pati termodifikasi dengan sifat fisik yang berbeda nyata antar perlakuan maupun pati alaminya. Modifikasi pati ganyong dengan HMT pada suhu 80 °C, waktu 8 jam, kadar air pati 15 % dan konsentrasi gum xanthan 1 % dapat menghasilkan pati ganyong yang sifat fisiknya mendekati tepung terigu kadar protein sedang dan berbeda dengan pati ganyong alami. Sifat fisik pati ganyong termodifikasi tersebut adalah SP 16,90 ± 0,48 g/g, IKA 10,28 ± 0,25 %, IAA 112,58 ± 0,38 %, DP 0,94 ± 0,11 mL/g, dan DK 0,73 ± 0,026 g/mL.Kata kunci: Pati ganyong; gum xanthan; HMT; modifikasi; sifat fisik ABSTRACT Modification of Canna starch through heat-moisture treatment (HMT) and gum xanthan (GX) treatment was conducted to improve the disadvantage of natural Canna starch in order to expand its usage in food industry, especially for bakery products. The research was arranged in a factorial randomized complete block design with three factors (temperature, incubation time, and GX concentrations) and three replications for each factor. The modified Canna starch by HMT possessed water content of 15 % as well as combination of temperature (80 °C and 100 °C), periods (8 and 16 hours) and concentration of GX (0; 0.5; 1; 1.5 and 2 %). The observed variables were the swelling power, water solubility index, water absorption index, baking expantion, and bulk density of modified Canna starch. The result showed that the modification of Canna starch by temperature, time of HMT and concentration GX produced modified starch with physical properties that significantly differ among treatments and natural starch. Modified Canna starch by treatments of 80 °C, 8 hours, and 1 % xanthan gum concentration showed had swelling power 16.90 ± 0.48 g/g, water solubility index 10.28 ± 0.25 %, water absorption index 112.58 ± 0.38 %, baking expantion 0.94 ± 0.11 mL/g and bulk density 0.73 ± 0.026 g/mL which alike with wheat flour so that it can be further developed as wheat flour substitute on bakery products.