No abstract

Nowadays, consumers are demanding for minimally processed, additive-free, high quality, fresh-like and microbiologically safe foods. However, as food deterioration is the constant threat along the entire food chain, food preservation remains as necessary today as in the past. In this paper, several citrus essential oils, including sweet orange, lemon and lime essential oil applied directly in fresh orange juice as a natural preservative, were analyzed for their antimicrobial activity. The antimicrobial activity of each citrus essential oil was assessed against Saccharomyces cerevisiae, Lactobacillus plantarum and Aspergillus niger using broth macrodilution. Among all citrus essential oils tested, sweet orange essential oil with 0.10% concentration showed significant antimicrobial activity against microorganisms tested. Hence, it was chosen to be applied in the fresh orange juice. Then, shelf life analysis was conducted during 7 d of storage at 5 °C and during 2 d of storage at 25 °C using selected concentration of the selected citrus essential oil in the fresh orange juice. Based on the results obtained, the addition of sweet orange essential oil with 0.10% concentration was not able to prolong the shelf life of the fresh orange juice according to the Indonesian National Standard (SNI). However, the formulation of fresh orange juice itself was able to improve its shelf life when compared to the shelf life of the commercial orange juice.

No abstract

Calcium absorption of standard milk is influenced by types of fat, other than types of calcium salts, vitamin D, PTH hormone, etc. However, calcium absorption on different fat content, particularly on milk, has not been reported. The purpose of this study was to determine the effect of the fat content of milk on the absorption of calcium carbonate and calcium phosphate mixture in rats. Experiments were conducted using 24 male Sprague Dawley rats fed with low-fat milk (0.5% fat), high-fat milk (26% fat), standard milk (8% fat) and without milk for three weeks. Amount of feed consumed, feces and urine samples were collected to determine the amount of absorbed calcium for five days in the third week. Calcium content in the samples was analyzed using AAS (Atomic Absorption Spectrophotometry). The results showed that there were no difference in calcium carbonate and calcium phosphate absorption among rats fed with low-fat milk, high-fat milk and standard milk. The calcium absorption level from milk reached an average of around 98.67±0.22%. The absorption level of calcium carbonate and calcium phosphate mixture from milk was higher than control rats that were not fed with any milk. Fat content in milk did not affect the absorption of calcium carbonate and calcium phosphate mixture, but the milk consumption could increase the calcium absorption, compared to control.