Judul: Sensory Optimization of Chocolate Bar Products from XYZ Industry using CATA, RATA, and JAR Methods
Abstrak: Indonesia is a major player in the global cocoa production and export industry, yet domestic chocolate consumption remains low, averaging only 0.10 kg per person per year compared to higher consumption rates in Europe. This low consumption is attributed to subpar chocolate products and the consumer perception that chocolate is an unhealthy food associated with obesity. XYZ industry, based in Magelang Regency, Central Java, aims to support local cocoa farmers and produce healthier, vegan chocolate bars with functional benefits. However, their current chocolate bar products do not consistently meet consumer taste preferences, despite their health advantages. Sensory evaluation was conducted on 12 chocolate bar products using Check-All-That-Apply (CATA), Rate-All-That-Apply (RATA), and Just-About-Right (JAR) methods to understand consumer perceptions and preferences. CATA identified Solid Energy Chocolate as the ideal product due to its nutty and cereal attributes. RATA analysis provided detailed sensory profiles, revealing that Sea Salt & Almond, Lactation Chocolate, and Solid Energy were most preferred by consumers. JAR method results indicated that the majority of attributes in the Solid Energy Chocolate variant were considered “too little,” but the results were inconclusive due to panelist misinterpretation of intensity scales. Sensory optimization needs to be performed on 6 chocolate bar variants that has the percentage of consumer’s satisfaction low, to better meet consumer preferences., Indonesia adalah pemain utama dalam industri produksi dan ekspor kakao global, namun konsumsi cokelat domestik tetap rendah, rata-rata hanya 0.10 kg per orang per tahun dibandingkan dengan tingkat konsumsi yang lebih tinggi di Eropa. Konsumsi yang rendah ini disebabkan oleh produk cokelat yang kurang memadai dan persepsi konsumen bahwa cokelat adalah makanan tidak sehat yang berkaitan dengan obesitas. Industri XYZ, yang berbasis di Kabupaten Magelang, Jawa Tengah, bertujuan untuk mendukung petani kakao lokal dan memproduksi cokelat batangan yang lebih sehat, vegan, dan memberikan manfaat fungsional. Namun, produk cokelat batangan mereka saat ini tidak secara konsisten memenuhi preferensi rasa konsumen, meskipun memiliki keunggulan kesehatan. Evaluasi sensori dilakukan pada 12 produk cokelat batangan menggunakan metode Check-All-That-Apply (CATA), Rate-All-That-Apply (RATA), dan Just-About-Right (JAR) untuk memahami persepsi dan preferensi konsumen. CATA mengidentifikasi Solid Energy Chocolate sebagai produk ideal karena atributnya yang nutty dan sereal. Analisis RATA memberikan profil sensori yang mendetail, mengungkapkan bahwa varian Sea Salt & Almond, Lactation Chocolate, dan Solid Energy adalah yang paling disukai oleh konsumen. Hasil metode JAR menunjukkan bahwa mayoritas atribut pada varian Solid Energy Chocolate dianggap “terlalu sedikit,” namun hasil ini tidak konklusif karena kesalahan interpretasi intensitas oleh panelis. Optimalisasi sensori dirasa perlu dilakukan pada 6 varian cokelat batangan yang memiliki persentase kepuasan konsumen rendah, agar dapat memenuhi preferensi konsumen.
Keyword: sensory evaluation, CATA, RATA, JAR, Chocolate bar, Check-all-that-apply, Rate-all-that-apply, Just-about-right

Judul: Evaluation Sensory Profile of Coconut Yogurt Chocolate Product PT XYZ Using Check-All-That-Apply (CATA) Method
Abstrak: Kesadaran masyarakat untuk hidup sehat semakin meningkat sehingga menyebabkan berkembangnya pangan yang memberikan efek kesehatan atau dikenal dengan pangan fungsional. Salah satu jenis pangan fungsioal adalah yogurt. Yogurt yang banyak dikenal masyarakat saat ini adalah yang berasal dari susu sapi. Kelemahan penggunaan yogurt berbahan dasar susu sapi adalah tidak semua masyarakat dapat mengonsumsinya, karena alasan dapat menimbulkan alergi, menyebabkan lactose intolerant, dan vegan. Penelitian ini bertujuan untuk mengidentifikasi profil sensori pada proses pengembangan produk Coconut Yogurt Chocolate di PT XYZ berdasarkan persepsi konsumen. Metode evaluasi sensori berbasis konsumen yang digunakan pada penelitian ini adalah Check-All-That Apply (CATA). Penelitian ini dilakukan dengan beberapa tahapan yaitu persiapan dan pengujian kuisioner, survei konsumen, focus group discussion (FGD), persiapan dan pengujian tiga sampel dengan metode CATA (jenis cocoa mass natural, cocoa mass alkalized dan cocoa powder), dan analisis data menggunakan perangkat lunak XLSTAT. Hasil pengujian menunjukkan bahwa atribut sensori ideal menurut konsumen adalah sweet aftertaste, rasa gurih, sour aroma, coconut flavor, sweet flavor, chocolate flavor, chocolate aroma, coconut milk aroma, dan mouthcoat mouthfeel. Produk cocoa powder paling mendekati dengan produk ideal dan memiliki atribut sensori yang ada pada produk ideal dan liking. Atribut needstate diperoleh hasil yang berbeda setiap sampel, atribut needstate ideal menurut konsumen adalah health maintenance dan pleasure, sedangkan yang mempengaruhi tingkat kesukaan (liking) adalah relaxation dan pleasure. Rekomen dasi perbaikan produk mengacu pada atribut ideal dan liking, atribut yang termasuk ke dalam dua kelompok tersebut antara lain rasa manis (sweet), sweet aftertaste, mouthcoat mouthfeel, chocolate aroma, dan chocolate flavor. PT XYZ dapat menggunakan sampel 3 sebagai peluncuran produk baru karena telah sesuai dengan preferensi, kebutuhan, dan keinginan atau kesukaan (hedonik) konsumen., Public awareness for healthy living is increasing, causing the development of foods that provide health effects or known as functional foods. One type of functional food is yogurt. Yogurt that is widely known to the public today is derived from cow's milk. The disadvantage of using yogurt made from cow's milk is that not all people can eat it, for reasons it can cause allergies, cause lactose intolerance, and are vegan. This study aims to identify the sensory profile in the product development process of Coconut Yogurt Chocolate at PT XYZ based on consumer perceptions. The consumer-based sensory evaluation method used in this study is Check-All-That-Apply (CATA). This research was conducted in several stages, namely the preparation and testing of questionnaires, consumer surveys, focus group discussions (FGD), preparation and testing of three samples using the CATA method (types of natural cocoa mass, alkalized cocoa mass and cocoa powder), and data analysis using software XLSTAT. The test results show that the ideal sensory attributes according to consumers are sweet aftertaste, savory taste, sour aroma, coconut flavor, sweet flavor, chocolate flavor, chocolate aroma, coconut milk aroma, and mouthcoat mouthfeel. Cocoa powder products are closest to the ideal product and have the sensory attributes that exist in the ideal product and liking. Need state attribute obtained different results for each sample, the ideal need state attribute according to consumers is health maintenance and pleasure, while those that affect the level of liking are relaxation and
Keyword: Check-All-That-Apply (CATA), Chocolate, Coconut Milk, Sensory Evaluation, Yogurt

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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