In this paper the experiments on microbiological quality and aroma components of yoghurt samples produced from long life goat's and cow's milk, and also from milks with 2% milk powder addition, during 9 days of refrigerated storage are described. Milk fermentation was conducted at 42 °C for 6 h. During days 1, 3, and 9 of storage the changes in acidity (pH value and lactic acid percent), viable counts of streptococci and lactobacilli and aroma components (acetaldehyde and diacetyl) were determined. Lower pH values and smaller lactic acid concentrations were found in control yoghurt samples. Viable counts of streptococci decreased during storage (from 1.01×10 8 to 3.97×10 7 CFU ml -1), whereas the viable counts of lactobacilli increased in all samples (from 6.95´10 6 to 2.32×10 7 CFU ml -1). The increase in count of lactobacilli was the greatest in goat's milk yoghurt samples. On the ninth day of storage, ?logN between cow's and goat's milk yoghurt samples was 0.2. Acetaldehyde in yoghurts decreased during storage time from 5.47 mg kg -1 (on day 1) to 1.05 mg kg -1 (on day 9). Both control yoghurt samples had lower acetaldehyde concentration than the supplemented samples. During nine days of storage, a significant increase in diacetyl content of yoghurt samples (from 14.20 mg kg -1 on the first day to 18.65 mg kg -1 on day 9) was noticed. goat's milk yoghurts, especially that manufactured without milk powder addition, had very soft consistency, but no syneresis was observed.
Lycopene, the pigment responsible for the characteristic deep red colour of ripe tomatoes and their products, plays an important role in human health. The stability of lycopene in tomato purée during storage was studied. Tomato purée was prepared from tomatoes grown in three different geographical regions of Croatia during two seasons. The samples of tomato purée were stored in the dark at 5, 15 and 25 °C and under light at 25 °C during a period of 6 months with constant monitoring of the changes of lycopene content. At the beginning of the storage there was no statistically significant difference (P<0.05) in lycopene content between the samples and geographic origin, while season significantly (P<0.05) influenced lycopene content. The value of lycopene content in all tomato purée samples significantly decreased (P<0.05) with increasing storage time for all the treatments. Light exposure significantly (P<0.05) facilitated degradation of lycopene.
Authors:M. Krpan, N. Major, Z. Šatalić, and M. Hruškar
Human breast milk, infant formula, and follow-up milks were tested by a commercial electronic tongue (αAstree, Alpha MOS) with the aim to determine taste diversity, since it has been recently shown that infants exposed to different tastes early in life, develop different food preference at a later age. Human milk (36 samples) were obtained from 13 lactating women, while 12 samples of infant formula and 14 samples of follow-up milk were obtained from the Croatian market and opened prior to analysis. Human breast milk samples showed a much higher diversity than both infant formulae and follow-up milks. These results suggest that breast-fed infants are exposed to a broader sensory experience, while formula fed infants are exposed to less diverse taste. Future studies will probably answer how this influences later food choice, taste preferences, and consequently, risk of obesity and other chronic diseases.