Judul: Basic Taste Threshold and Preferences in Food Matrices by Multicultural Approach in Indonesia
Abstrak: Taste is the most important parameter for food acceptance. Each of the basic tastes; sweet, bitter, sour, salty, and umami, has its minimum concentration to be detected or identified by human senses, called threshold. Cross-cultural studies showed that eating habit was one of the factors that affect taste threshold and preference of food, associated with taste intensity in the food. Indonesia is an archipelagic country with multiethnic citizens with more than 740 ethnic groups. Each ethnic group has its unique food taste and eating habits. Bogor Agricultural University as one of the best university in Indonesia could be a good representative of Indonesian multiethnicity. First year undergraduate students are good representatives. They have lived in Bogor for a short time, thus it can be assumed that their eating habit based on ethnicity still remains. The aim of this study was to evaluate taste threshold of three basic tastes (sweet, bitter, and salty) and preference in food matrices (tea, coffee, and vegetable soup broth) of three ethnic groups in Indonesia. The other aims were to evaluate the influence of gender to taste threshold and preference in Indonesia and to evaluate the correlation between taste threshold and its preference in food matrices. This study was conducted in four stages: (1) preliminary study to determine concentration series of taste threshold and preference tests, (2) panelist recruitment, (3) evaluation of taste threshold and preferences in food matrices, and (4) data analysis. The panelists were first year undergraduate students in Bogor Agricultural University recruited from regional student organizations of three ethnic groups: Minangese, Javanese, and Nusa Tenggara. Recruitment criterias are age (17-25 years old) and having lived in the area of ethnic origin for 10 years minimum. Each ethnic group was represented by 30 panelists, with the proportion 60:40 for female and male. Sensory tests were conducted in Food Sensory Analysis Laboratory, SEAFAST Center, in individual booths on room temperature (25oC). Taste threshold determination was conducted by using three-alternative force choice (3-AFC) ascending concentration series method of limits (ASTM E679), while preference test was conducted using Rank-Rating method. Data analysis were using Microsoft Excel for Windows 2007 and SPSS 20. Analysis of questionnaire data showed that umami and sweet taste were dominantly found in Minangese, Javanese, and Nusa Tenggara foods. Minangese foods were uniquely dominant in spicy taste. The beverages from three ethnic groups were dominant in sweet taste. The average of sweet taste threshold of Indonesian was 6.027 mM of sucrose, 0.713 mM of caffeine for bitter taste, and 1.982 mM of NaCl for salty taste. Minangese had the highest threshold for sweet taste (8.139 mM of sucrose) and bitter taste (0.770 mM of caffeine). Javanese had the highest threshold of salty taste (2.177 mM of NaCl). Panelists from Nusa Tenggara had the lowest threshold of all tastes (4.070 mM of sucrose, 0.671 mM of caffeine, and 1.895 mM of NaCl). Statistical analysis showed that ethnic groups have significantly affected sweet taste threshold (p=0.034) between Nusa Tenggara and Minangese. Gender differences showed that female panelists had lower threshold of all tastes. Statistical analyses of threshold differences
Keyword: AFC, gender, multicultural, preference, taste threshold.

Judul: Sensory threshold dan preferensi rasa manis dalam matriks minuman pada orang sehat dengan riwayat keluarga penderita diabetes
Abstrak: Diabetes adalah penyakit gangguan metabolisme glukosa yang sering disebut dengan persistent hyperglycemia. WHO menyatakan bahwa penyakit diabetes menurun secara genetika. Tujuan penelitian ini adalah untuk menentukan ambang deteksi dan ambang pengenalan rasa manis, preferensi rasa manis (rating kesukaan), dan asupan sukrosa harian pada grup studi (orang sehat dengan keturunan diabetes, n=25) dan grup kontrol (orang sehat tanpa keturunan diabetes, n=25). Uji ambang deteksi menggunakan metode 3-AFC (Ascending Forced Choice) ASTM E-679 sedangkan uji ambang pengenalan menggunakan metode ASTM E-679 termodifikasi. Uji preferensi rasa manis dilakukan dengan metode rating kesukaan skala garis. Estimasi asupan sukrosa dihitung dengan metode pencatatan menu harian selama tiga hari. Konsentrasi ambang deteksi rasa manis grup studi dan kontrol adalah 0.30% dan 0.26% (p=0.232). Konsentrasi ambang pengenalan rasa manis grup studi dan kontrol adalah 0.30 % dan 0.36 % (p=0.091). Rating kesukaan teh manis pada konsentrasi gula 1.5 dan 3 % berbeda nyata dengan konsentrasi gula 6, 10, 12 % baik pada grup kontrol maupun grup studi (p=0.000). Rating kesukaan tertinggi pada grup studi dan kontrol terletak pada konsentrasi gula 12% dan 10%. Estimasi jumlah sukrosa pada grup studi dan kontrol adalah 110 dan 85.6 gram (p=0.223). Hasil uji statistik ambang deteksi, ambang pengenalan, preferensi dan estimasi asupan sukrosa menunjukkan hasil yang tidak berbeda nyata pada kedua grup.
Keyword: threshold rasa manis, 3-AFC, food diary 3-days, rating kesukaan, diabetes

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh.
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. ,,,
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular.