The effect of water activity (aw) and length of storage on the fungal infection and quality of rice and milled rice in East Java (Indonesia)

anglais. Studies of the effect of water activity (Aw) and length of storage on the severity of fungal infection and quality of rice and milled rice of IR 64 and Semeru in East Java, has been conducted by using split-plot and factorial designs with three replicates. Four species of field fungus were found, namely Fusarium sp., Drechslera sp., Curvularia sp. and Alternaria sp. and different species were found in the storage, namely Aspergillus sp., Penicillium sp., Mucor sp. and Rhizopus sp. The fungal infection was positively correlated with Aw. Under conditions of Aw 0.7, the severity of fungal infection in rice and milled rice from Banyuwangi were 11.5 percent and 23.6 percent respectively, and in rice from Malang was 22.38 percent. The severity of the infection of milled rice from Malang was not significantly influenced by Aw, but it was influenced by variety of rice. At Aw 0.7, the severity of infection in IR 64 and Semeru from Malang were 31.89 percent and 20.47 percent respectively. The severity of fungal infection of both rice and milled rice from Banyuwangi under conditions of Aw 0.9 were 19.22 percent and 36.86 percent respectively, and in rice from Malang was 25.85 percent. The length of storage significantly influenced the severity of fungal infection, the percentage of germination and growth of seedlings as well as the content of protein and amylose and colour of both rice and milled rice. The length of storage was negatively correlated with the content of protein and amylose

indonésien. Dua percobaan untuk mengetahui pengaruh aktivitas air (Aw) dan lama penyimpanan terhadap jenis dan besarnya serangan jamur pada gabah dan beras IR64 dan Semeru asal Malang dan Banyuwangi, Jawa Timur, telah dilakukan dengan menggunakan rancangan petak terbagi dan rancangan acak faktorial dengan tiga ulangan. Dari percobaan tersebut diketemukan empat jenis jamur lapang, yakni Fusarium sp., Drechslera sp; Curvularia sp. dan Alternaria sp., serta empat jenis jamur pada tempat penyimpanan, yakni Aspergillus sp., Penicillium sp., Mucor sp., dan Rhizopus sp. Persentase serangan jamur pada gabah dan beras lebih besar dengan semakin besarnya Aw. Pada Aw 0,7 serangan jamur pada gabah dan beras asal Banyuwangi masing-masing sebesar 11,5 persen dan 23,67 persen, serangan jamur pada gabah asli Malang sebesar 22,38 persen. Persentase serangan jamur pada beras asal Malang tidak dipengaruhi secara nyata oleh Aw, tetapi dipengaruhi oleh varietas beras. Pada Aw 0,7 serangan jamur pada beras IR64 dan Semeru masing-masing sebesar 31,89 persen dan 20,47 persen. Selanjutnya pada Aw 0,9 serangan jamur pada gabah dan beras asal Banyuwangi masing-masing sebesar 19,22 persen dan 36,86 persen