Tyas Utami
Jurusan Teknologi Pangan dan Hasil Pertanian, Fakultas Teknologi Pertanian, Universitas Gadjah Mada, Yogyakarta

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Isolasi dan Identifikasi Bakteri Asam Laktat Proteolitik dari Susu Kedelai yang Terfermentasi Spontan Yusmarini, Yusmarini; Indrati, Retno; Utami, Tyas; Marsono, Yustinus
Jurnal Natur Indonesia Vol 12, No 1 (2009)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (188.878 KB) | DOI: 10.31258/jnat.12.1.28-33

Abstract

Lactic acid bacteria is a group of bacteria with proteolytic activities enambling to grow on protein rich substratesuch as soymilk. This research was aim to isolate and identify lactic acid bacteria with have proteolytic activityfrom spontaneous fermented soy milk. Sixteen isolates out of 26 colonies isolated from fermented soymilk arepresumed as lactic acid bacteria. Among these 16 isolates, only 3 of them showed proteolytic activity. These threeisolates were further identify morphologically and only two isolates identified as Lactic Acid Bacteria, namelyR.1.3.2 and R.11.1.2. The ability of these isolates to produce acid and protease were observed. The results showedthat isolate R 1.2.3 higher ability in producing protease.
Fatty Acids Profile, Oxidative and Hydrolysis Stability of Virgin Coconut Oil and Palm Stearin Based Human Milk Fat Analog Karouw, Steivie; Suparmo; Hastuti, Pudji; Utami, Tyas
International Coconut Community Journal Vol 30 No 2 (2014): CORD
Publisher : International Coconut Community

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (506.191 KB) | DOI: 10.37833/cord.v30i2.71

Abstract

The objectives of the research are to evaluate fatty acids profile, oxidative and hydrolysis stability of human milk fat (HMF) analog by using virgin coconut oil (VCO) and palm stearin as raw materials. The HMF analog was synthesized through enzymatic interesterification catalyzed by lipase from Rhizomucor miehei. The fatty acid profiles of interesterification products were monitored using gas chromatography. Oxidative stability test was carried out for up to 72 hours at 60oC. The peroxide value was measured during 0, 24, 48 and 72 hours of storage duration. Hydrolysis stability test was held for up to 8 days at room temperature. The free fatty acid content was monitored during 0, 2, 4, 6 and 8 days of storage. The results showed that the resulted HMF analog having high percentage of palmitic acid in the sn-2 position, similar to that of HMF. The palmitic acid content in the sn-2 position was around 39.71%. The MCFAs were esterified in the sn-1 and sn-3 position and the main fatty acid constituent was lauric acid of 39.37%. The obtained HMF analog was stable to oxidative and hydrolysis deterioration as indicated by the peroxide value and free fatty acid content during storage.
Snacking Habits and Level Acceptance of Freeze-Dried Probiotic Yogurt Snacks by Children Aini, Novia Nur; Yanti, Rini; Fibri, Dwi Larasatie Nur; Utami, Tyas; Rahayu, Endang
agriTECH Vol 45, No 2 (2025)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.90246

Abstract

Stunting in children is a significant problem worldwide, specifically in developing countries. One of the contributing factors to this condition is dysbiosis, characterized by an imbalance in gut microbiota and is commonly observed in affected patients. To reduce the prevalence of stunting, it is critical to provide products that are rich in protein, calcium, and probiotic. In this context, freeze-dried probiotic yogurt snacks can be used as an effective solution due to their high nutritional value, ability to preserve probiotic cell viability, and extended shelf life. Therefore, this study aims to determine snacking habits and level of acceptance of yogurt snacks among children through a sensory evaluation. The result showed that parents often considered taste, health benefits, and price when purchasing snacks. Meanwhile, children showed a high preference for freeze-dried probiotic yogurt snacks, particularly due to their appealing shape. Panelist parents also considered the products to be necessary, recommended, and an alternative to unhealthy snacks. Therefore, these products may be suitable for upper-middle-class consumers due to their higher prices and will require taste improvement to increase consumer acceptance among children.
Pulp Reduction and Addition of Indigenous Microorganisms as Starter: Effects on Fermented Cocoa Bean Characteristics Fajariyah, Anna; Rahayu, Endang Sutriswati; Farianti Djaafar, Titiek; Utami, Tyas; Anggraini Suroto, Dian; Marwati, Tri
agriTECH Vol 45, No 3 (2025)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.86796

Abstract

Indonesian cocoa smallholder plantations frequently produced low-quality dry beans due to poor postharvest handling, necessitating improvements through controlled fermentation. This study evaluated pulp reduction and local microorganism starter addition in farmer-level cocoa fermentation on the microbiological, physical, and chemical properties of cocoa beans. Using a Factorial Randomized Block Design, the research included four experimental units: 1) spontaneous fermentation, 2) reduced-pulp fermentation, 3) starteradded fermentation, and 4) reduced-pulp and starter-added fermentation. Pulp was reduced by approximately 35%, and microorganisms utilized were Candida famata HY-37, Lactiplantibacillus plantarum subsp. plantarum HL-15, and Acetobacter sp. HA-37. The five-day fermentation resulted in the growth of yeast, lactic acid bacteria (LAB), and acetic acid bacteria (AAB). This was indicated by a peak fermentation temperature of 45 °C, a decrease in fermentation pH to 3.7, and a decrease in bean pH to 4.7, in line with total titratable acidity increasing. Over the course of two days, the Fermentation Index aboved 1.0. Pulp reduction raised fermentation temperatures and resulted in an earlier peak by the third day. The use of a starter can suppress fungal growth during fermentation. The total fungal population is lower in combining pulp reduction with starter addition fermentation cocoa beans. The physical properties met the Indonesian National Standard (SNI) 2323:2008/Amd I:2010. The chemical characteristics showed that the Fermentation Index was above 1.0, the bean pH values were from 5.16 to 5.36, and the reducing sugar contents were from 1.50 to 1.69 %. Incorporating starter treatment effectively inhibited fungal growth during fermentation. The combination of reducing pulp and adding starter inhibited fungal growth in fermented cocoa beans without affecting their physical and chemical properties.