Coconut oil as an alternative to butter and shortening in bread making.

The characteristics of bread prepared with coconut oil were investigated to determine whether it can be used as an alternative to butter and shortening. Loaf height of the bread increased by adding butter and shortening water content of bread containing oils and fats was lower than that without oils and fats, and baking loss increased with decreasing water content. The addition of oils and fats influenced the baking color of bread and hindered the hardening of bread samples over time. Moreover, the addition and type of oils and fats influenced the crust density of bread samples and dough expansion. Furthermore, numerous fine bubbles were present in bread samples without oils and fats, whereas the size and number of bubbles increased and decreased in bread samples containing oils and fats, respectively. The band concentrations of insoluble proteins at approximately 39, 41, and 48 kDa in freeze-dried bread samples without oils and fats were significantly lower than those containing oils and fats. Thirty volatile compounds were detected in all bread samples tested, and the number was high in the following order: bread samples with butter, shortening, and coconut oil, and without oils and fats. However, sensory evaluation showed no significant differences among all bread samples tested. Therefore, it was suggested that bread containing coconut oil had the same characteristics as that containing butter and shortening. PRACTICAL APPLICATION: Butter and shortening are usually used in bread making, although bread prepared with coconut oil can possess the same characteristics as that containing them. Therefore, this study evaluated the characteristics of bread prepared with coconut oil and revealed that use of coconut oil enabled a vegan bread with reduced environmental impact because coconut oil is a vegetable-derived oil that does not require the cutting of tropical rainforests.

Relationship between intracellular protein denaturation and irreversible inactivation of Saccharomyces pastorianus by low-pressure carbon dioxide microbubbles.

To clarify the relationship between irreversible inactivation and intracellular protein denaturation of Saccharomyces pastorianus by low-pressure carbon dioxide microbubbles (CO2 MB) treatment, a storage test of S. pastorianus cells treated with CO2 MB was performed, and the effect on the intracellular protein was investigated. In the storage test, the S. pastorianus population, which decreased below the detection limit by CO2 MB treatment at a temperature of 45 and 50°C (MB45 and MB50), and thermal treatment at a temperature of 80°C (T80), remained undetectable during storage for 3 weeks at 25°C. However, 4.1 and 1.3-logs of the S. pastorianus populations, which survived after CO2 MB treatment at temperatures of 35 and 40°C (MB35 and MB40), increased gradually during storage for 3 weeks at 25°C. Insolubilization of intracellular proteins in S. pastorianus increased with increasing the temperature of CO2 MB treatment. Activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) identified as one of the insolubilized proteins increased at MB35 and MB40 than non-treatment but disappeared at MB45 and MB50, and T80. Therefore, it was revealed that S. pastorianus cells inactivated below the detection level by CO2 MB treatment did not regrow and that the denaturation of intracellular proteins of S. pastorianus was caused by CO2 MB and thermal treatments. Furthermore, it was suggested that denaturation of intracellular vital enzymes was an important factor for achieving irreversible inactivation of S. pastorianus by CO2 MB and thermal treatments.