Judul: IPB (Bogor Agricultural University)
Abstrak: Through a nutritional improvement project, Bogor District had donated powdered milk formula (PMF) for severe malnutrition children below five years. Powdered milk formula was assumed as an unsterilized product, because it might contain microbes. To evaluate the bacterial contaminant, forty eight samples of donated PMF were taken proportional from ten Puskesmas in Kabupaten Bogor. To evaluate the home prepared milk formula, 50 samples of PMF, reconstitution formula, drinking water, drinking equipment, and hand swabs, was taken from the mothers. To evaluate the knowledge, attitude and behavior of the safety of reconstituted and home storage of PMF, 50 questioners were given to the mothers. Microbe samples were analyzed for total aerobic plate counts, Bacillus cereus and Clostridium perfringens. The median counts for total aerobic count were 4.7 x 102 CFU/g. The value of total aerobic count less than 1 x 104 CFU/g is used as a basic standard for baby food (SNI 01-7111.1-2005). Approximately 30.6% products were contaminated by B. cereus with a median count 1.4 x 102 CFU/g. The presences of C. perfringens in all samples were not detected. Australian and New Zealand Food Standard (Standard 1.6.1-Microbiological Limit for Food 2001) for follow-on milk formula were used as a basic standard for of B. cereus and C. perfringens and the acceptance number of B. cereus were 102 CFU/g and C. perfringens <1 CFU/g. All of the follow-on milk formulas were safe to be distributed and consumed. Attention must be taken, because 4 samples (26.7%) contained B. cereus was able to produce enterotoxin. Improper home storage could promote the growth of aerobic microbe and B. cereus. Improper preparation would promote the growth of B. cereus which present initially at low level (mean 7.8 x 10 CFU/g) and became 1.6 x 103 CFU/ml after the reconstitution had done. C. perfringens emerge at 4 samples (mean 1.5 x 10 CFU/ml) after the reconstitution. Several isolate of B. cereus (4 from PMF, 13 from opened PMF, and 2 from reconstitution formula) showed a possibility to produce diarrheagenic enterotoxin while the isolate of C. perfringens did not show it. The spore of B. cereus and C. perfringens could survive in different preparation temperature (25, 35 and 70oC for B. cereus and 25, 47, 70oC for C. perfringens) and storage abuse (with <50 and >70% humidity; opened, closed and opened twice a day in observation). Bacteria population increased .1 log within 3 hours at room temperature (28-29oC). The microorganism could survive from dry condition, especially when aw of the formulas increased cause of storage abuse. The result from questioners and microbe samples shown, that mothers knowledge of milk safety were correlated to the number of their children (r=-0.34). The carefullness attitude of mothers were correlated to the knowledge of milk safety (r=0.51), the family income (r=0.28) and the number of their children (r=-0.40). The healthy behaviour of mothers were correlated to knowledge of milk safety (r=0.31), the family income (r=0.37), and carefulness attitude (r=0.30). It is suggested, that changing mothers knowledge of milk safety are necessary.
Keyword: Enterotoksin, Powdered milk formula, Storage and preparation, West Java

Judul: Model Estimasi Pertumbuhan Cronobacter spp. Berdasarkan Praktik Penyiapan, Pemberian dan Penyimpanan Susu Bubuk Formula Bayi pada Tingkat Rumah Tangga di Jakarta Pusat
Abstrak: This study was conducted to gather information on how to prepare, give and storage the powdered infant formula by mothers at home and to know about temperature and time profile since the reconstitution of PIF, give to the baby and storage of PIF that had been reconstituted using the descriptive method with survey approach. Temperature and time profile data obtained from this survey would be used to estimate the growth of Cronobacter spp. using the FAO/WHO Quantitative Risk Assessment Model of Cronobacter spp. in PIF, so it could provide recommendation of practice scenarios of preparation, giving and storage of PIF which did not pose a risk of Cronobacter spp. infection. From this survey, there were 16 scenarios of preparation, giving and storage of PIF which represented the practices by 30 respondents. Scenarios were selected based on the stages of respondents did in preparing and handling PIF and temperatures of water which were used to reconstitute PIF. The result of this study showed that 16th scenario was the most at risk scenario for Cronobacter spp. infection, both on the assumption of initial contamination level of 1 CFU/100g or 3 CFU/100g. That was because final contamination levels of Cronobacter spp. in 16th scenario exceeded the initial dose estimate of Cronobacter spp. infection that is equal to 3 CFU/100g. In 16th scenario, by assuming initial contamination levels to 1 CFU/100g and 3 CFU/100g, the final contamination levels that were obtained successively were 89.12 CFU/100g and 269.15 CFU/100g. Lag phase of 16th scenario was 23 minutes. In 16th scenario, there were milk storage stage at room temperature for 4 hours that could cause a risk of Cronobacter spp. growth. 7th until 16th scenario could cause a risk of Cronobacter spp. infection if the assumption of initial contamination level of Cronobacter spp. in PIF was 3 CFU/100g. 1st until 6th scenario were scenario that were secure against infection of Cronobacter spp., both on the assumption of initial contamination level of 1 CFU / 100g or 3 CFU / 100g. In this study, water temperatures to reconstitute PIF were not significantly affect to the growth of Cronobacter spp., but the milk storage for too long as in the 15th and 16th scenario, respectively, ie for 2 hours and 4 hours.
Keyword: Bogor Agricultural University (IPB), FAO/WHO, reconstitute, powdered infant formula, Cronobacter spp

Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf