No abstract

Carotenoids—natural fat-soluble pigments—have attracted considerable attention because of their potential to prevent of various diseases, such as cancer and arteriosclerosis, and their strong antioxidant capacity. They have many geometric isomers due to the presence of numerous conjugated double bonds in the molecule. However, in plants, most carotenoids are present in the all-E-configuration. (all-E)-Carotenoids are characterized by high crystallinity as well as low solubility in safe and sustainable solvents, such as ethanol and supercritical CO2 (SC-CO2). Thus, these properties result in the decreased efficiency of carotenoid processing, such as extraction and emulsification, using such sustainable solvents. On the other hand, Z-isomerization of carotenoids induces alteration in physicochemical properties, i.e., the solubility of carotenoids dramatically improves and they change from a “crystalline state” to an “oily (amorphous) state”. For example, the solubility in ethanol of lycopene Z-isomers is more than 4000 times higher than the all-E-isomer. Recently, improvement of carotenoid processing efficiency utilizing these changes has attracted attention. Namely, it is possible to markedly improve carotenoid processing using safe and sustainable solvents, which had previously been difficult to put into practical use due to the low efficiency. The objective of this paper is to review the effect of Z-isomerization on the physicochemical properties of carotenoids and its application to carotenoid processing, such as extraction, micronization, and emulsification, using sustainable solvents. Moreover, aspects of Z-isomerization methods for carotenoids and functional difference, such as bioavailability and antioxidant capacity, between isomers are also included in this review.

We argue two alternative routes that lead entrepreneurial start-ups to acquisition outcomes instead of liquidation. On one hand, acquisitions can come about through the control route with external financers such as venture capitalists (VCs). VCs take control through their board seats along with other contractual rights that can bring about changes in a start-up necessary to successfully attract a strategic acquirer. Consistent with this view, we show that VCs often replace the founding entrepreneur as CEO long before an acquisition exit. On the other hand, acquisitions can come about through advice and support provided to the start-up, such as that provided by an incubator or technology park. Based on a sample of 251 Crunchbase companies in the U.S. over the years 2007 to 2014, we present evidence that is strongly consistent with these propositions. Further, we show that the data indicate a tension between VC-backing of start-ups resident in technology parks insofar as such start-ups are slower to become, and less likely to be, acquired.

No abstract

Recent studies have shown that Z-isomers of astaxanthin have greater bioavailability and biological activity than the all-E-isomer. Hence, it is important to develop efficient and practical Z-isomerization methods. This study attempted to establish a continuous-flow isomerization system for (all-E)-astaxanthin in subcritical ethanol. Specifically, the effects of temperature, pressure, time, and addition of antioxidants and a natural catalyst, allyl isothiocyanate, on the Z-isomerization and degradation were investigated. Continuous high-temperature processing (>140 °C) efficiently promoted astaxanthin Z-isomerization within a few minutes, but simultaneously accelerated its degradation. We found that the thermal degradation could be inhibited by adding specific antioxidants, especially ascorbic acid. Finally, using the continuous-flow system with ascorbic acid, 60.3% of total Z-isomer ratio of astaxanthin was achieved while inhibiting the degradation at 200 °C and 10 MPa in just 30 s. This efficient and environmentally friendly isomerization technology is an effective means for the production of Z-isomer-rich astaxanthin materials.

We argue two alternative routes that lead entrepreneurial start-ups to acquisition outcomes instead of liquidation. On one hand, acquisitions can come about through the control route with external financers such as venture capitalists (VCs). VCs take control through their board seats along with other contractual rights that can bring about changes in a start-up necessary to successfully attract a strategic acquirer. Consistent with this view, we show that VCs often replace the founding entrepreneur as CEO long before an acquisition exit. On the other hand, acquisitions can come about through advice and support provided to the start-up, such as that provided by an incubator or technology park. Based on a sample of 251 Crunchbase companies in the U.S. over the years 2007 to 2014, we present evidence that is strongly consistent with these propositions. Further, we show that the data indicate a tension between VC-backing of start-ups resident in technology parks insofar as such start-ups are slower to become, and less likely to be, acquired.

No abstract

No abstract