Judul: Kinetics of Quality Change of Carotenoids-rich Fat Powder Made From Red Palm Oil
Abstrak: Vitamin A Deficiency (VAD) has been a serious problem in Indonesia and the underlying cause is a diet which is insufficient in vitamin A. Food fortification is one of the strategy that can be implemented in Indonesia to reduce the burden of VAD and to improve vitamin A intake. Red palm oil, Indonesia’s abundant natural resource rich in carotenoids, is very potential to be used as food fortificant. Red palm oil can be used by direct addition to food product or by transforming it into carotenoids-rich fat powder before use. This study was to investigate the kinetics of quality changes of carotenoids-rich fat powder during storage and to determine the product shelf life, using Arrhenius accelerated method. Samples of fat powder were stored at 26C (ambient/room temperature) and at elevated temperatures of 35C, 40C, and 55C for 30 days, and samples were taken and analyzed every 5 days. As a reference, samples of fat powder were also stored at refrigeration of 12C. The results showed that fat powder underwent (i) some color changes, (ii) increase in free fatty acid and peroxide value, and (iii) decrease in carotene content and powder flowability. With carotene tolerance 50% of initial carotene, carotenoids-rich fat powder can be stored for 3 months and 11 days at ambient/room temperature with light protection.
Keyword: Bogor Agricultural University (IPB), Arrhenius accelerated method, Spray chilling, Palm Stearin, Red Palm Oil, Fat powder

Judul: Reformulasi Mikroenkapsulasi Minyak Sawit dengan Teknik Koaservasi, Pengeringan Lapis Tipis, dan Penyerapan SiO2
Abstrak: Cases of vitamin A deficiency (VAD) are often found in Indonesia. On the other hand, Indonesia is the largest palm oil producer in the world. The content of β-carotene, which is a provitamin A, in palm oil is relatively high, so that it has a great potential for overcoming cases of VAD. By microencapsulation process of palm oil, β-carotene content in palm oil will be more stable and have a longer shelf life. There are three methods used in this study, namely coacervation, thin-layer drying, and SiO2 absorption technique – teoretically they are suitable for encapsulating β-carotene in palm oil. Results of ANOVA test at 5% significance level showed that the differences in methods significantly affect water absorption, solubility in water, yield, efficiency, and the β-carotene content and retention of microencapsulate. The microencapsulate made by thin-layer drying method had the highest levels of β-carotene at 200.16 ppm with retention 68.89%. It also had low water absorption and high water solubility so that it can be applied as a premix.
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Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix