Judul: Volatilomics of Pan Cooked Patties Made from Beef, Pork, and Their Mixture
Abstrak: The demand for halal food is rising as Indonesia's Muslim population becomes more conscious of whether a food product is halal. In Indonesia, the most common meat used for patties is beef, which is more expensive than the other types of meat. As the main ingredient for patties is ground beef, it will be easier to adulterate with non-halal meat (pork) than foods that use whole meat as an ingredient. High beef costs contribute to adulteration of patty with pork. This study aimed to investigate the volatile characteristics of beef patties (100:0), pork patties (0:100), and their mixtures (75:25, 50:50, and 25:75), with and without additional seasonings (salt, pepper, and garlic), using SPME-GC-MS. Volatilome analysis was conducted to determine whether adding pork and seasoning affected the volatile organic metabolites (VOMs) of beef patties. Additional pork and seasonings in patties would change the volatile characteristics of the patty samples. Potential volatile marker compounds such as dimethyl disulfide (beef patties), naphthalene (mixed patties), and hexanal (pork patties) for the seasoned sample were determined. For unseasoned samples, the potential markers detected were 3,7,11-trimethyl-1- dodecanol, hexadecane, and nonanal for beef patty; naphthalene, octanal, and heptanal for mix patty; and hexanal, (E)- 2-octenal, (E)-2-heptenal, and 2-pentyl furan for pork patty. These results show that the meat ratio and seasonings changed the volatile characteristics of seasoned and unseasoned patties made from beef, pork, and their mixture. The lowest percentage of mixed meat that could be recognized as having changes in volatile characteristics was 25%.
Keyword: Volatile, Patty, Beef, Pork, Seasoning

Judul: Volatile Compounds Profiling and Markers Identification in Various Meat Broths Using SPME-GC-MS
Abstrak: Halal authentication for food products is critical worldwide, especially for muslim. Meat broth is one of the food products frequently adulterated with less expensive or non-halal ingredients. Halal authentication can be done using a DNA or protein-based approach, but this research aims to develop an authentication method that is easy, fast, and sensitive. Empirically, broth prepared from different type of meat has a different aroma. As a result, in this study, a volatilomics approach will be used to profile volatile compounds from various meat broths (chicken, pork, beef, goat, and duck) and to determine the typical marker compounds in each meat broth. The profile of volatile compounds was identified using the solid phase microextraction method combined with gas chromatography-mass spectrometry (SPME-GC-MS). Multivariate analysis was used to determine the differentiating compounds in meat broth: principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). The volatile compounds identified in this study for chicken, pork, beef, goat, and duck broth (89, 79, 76, 78, and 99 compounds, respectively). The aldehyde group is the most volatile compound in various meat broths because it has a low odor threshold, making it easy to detect and significantly contributing to the distinct flavor of the food matrix. The results of PCA analysis with two principal components can explain 59.5% of the data variation and show a trend of grouping meat broth based on its volatile compounds. Furthermore, the OPLS-DA model analysis revealed that the profile separation of volatile compounds from meat broth was superior to PCA analysis, with a variance value (R2X = 0.79; R2Y = 0.94) and a predictive coefficient value (Q2 = 0.75). Validation of the OPLS-DA model by performing a permutation test and a CV-ANOVA test, which shows that the model is valid and acceptable. The marker compounds were selected based on two criteria: volatile compounds that were positively correlated and had a high VIP (variable importance in projection) value. The main marker compounds contained in pork broth are fatty acids. Fatty acids were detected in the broth because the predominant matrix of the broth was lipid and water. Overall, the marker compounds in pork broth were dodecanoic acid, n-decanoic acid, heptadecanal, 2-pentadecanone, eugenol , 2-tridecanone, and (E,E)-2,4-nonadienal. According to the findings of this study, the volatilomics approach successfully distinguished various meat broths, thus enabling the marker compounds to be used as a database for halal authentication of processed meat products.
Keyword: authentication, broth, discriminant analysis, halal, volatilomics

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. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular