Kinetic Stability of Lutein in Freeze-Dried Sweet Corn Powder Stored under Different Conditions

Abstract

The powder of freeze-dried sweet corn was stored under different conditions at 4, 20 and 37℃ for 12 weeks, and the stability of lutein and its isomers during storage were studied. It was found that total lutein content declined depending on storage conditions and the kind of lutein isomer. The highest residual of all-trans-lutein was found stored at 4℃ with vacuum and dark. Under the storage of air and light at 37℃, major isomers 9-cis-lutein, 9'-cislutein, 13'-cis-lutein and 13-cis-lutein showed significant increases by 35.0, 50.0, 38.4 and 37.1%, respectively, of its original content after 12 weeks of storage, which indicated isomerization might take place during storage. The kinetics of all-trans-lutein degradation under different conditions followed first order kinetics well, the apparent rate constant values were lowest under vacuum and dark and highest under air and light at each storage temperature, confirming potential detrimental effects of oxygen and light on lutein loss.Keywords: freeze-dried sweet corn, lutein, storage, stability, kinetics IntroductionLutein, one of the important carotenoids, has gathered increasing attention due to their association with eye health. (Huck et al., 2000;Johnson, 2004). It is mostly found in fruits, vegetables, grains, and eggs (Perry et al., 2009). Lutein plays an important role in preventing cataracts and age-related macular degeneration (AMD), which is the leading cause of blindness among the elderly. Lutein acts as a blue-light filter and protects the underlying tissues from phototoxic damage (Ma, et al., 2012).Studies have also shown lutein in human plasma has antioxidative function such as the scavenging of free radicals and singlet oxygen and thus reducing the risk of certain cancers (Handelman, 2001;Schunemann et al., 2002).Sweet corn (Zea mays L.) contains significant amounts of lutein and other carotenoids and is becoming a popular vegetable in the Chinese diet (Scott and Eldridge, 2005;Niu et al., 2011). Freezedrying process of sweet corn is used to increase its shelf life with a minimal loss of nutrients, which may be a promising technique to avoid amounts of lutein decreased via heat degradation, several researchers have analyzed nutrient content in freeze-dried plant materials (Siriamornpun et al., 2012;Zhang et al., 2009;Kao et al., 2011), however few reports have evaluated the lutein content in processed corn under different storage conditions. Naturally, lutein is usually present in their all-transconfiguration, except for processing of food such as drying, heating, and cooking that affecting all-trans-lutein partially converted into their cis-isomers (Bengtsson et al., 2008; AparicioRuiz et al., 2011;Kao et al., 2012). Furthermore, storage time and storage conditions, such as oxygen, temperature and light, facilitate the formation of cis-isomers (Tang and Chen, 2000;Çinar, 2004).The nutritional consequences of cis/trans isomerization could be changed in bioavailability and physiological activity (Jabeen, et al., 2013). Literature data also suggest tha...

Lutein Esterification in Wheat Flour Increases the Carotenoid Retention and Is Induced by Storage Temperatures

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Changes and degradation kinetics of some bioactive compounds in dried Orthosiphon aristatus (Java tea) leaves during elevated temperature storage

“…Sharma and Maguer reported that the E a of lycopene degradation in tomato pulp solids stored at −20, 5 and 25 °C was in the range 19.87–27.74 kJ mol −1 . Lutein degradation E a in freeze‐dried sweetcorn during storage under vacuum and dark conditions was 32.40 kJ mol −1 , which was higher than in air and dark storage conditions (28.64 kJ mol −1 ) . E a for SEN and EUP degradation in OA leaves seems to be higher than for bioactive compounds reported above, providing a more stable storage environment in the indicated packages.…”

Carotenoid Composition and Changes in Sweet and Field Corn (Zea mays) During Kernel Development

“…The extraction of carotenoids in corn kernels was adapted from published procedures (Li et al 2014). The extraction of carotenoids in corn kernels was adapted from published procedures (Li et al 2014).…”

“…Carotenoid Extraction. The extraction of carotenoids in corn kernels was adapted from published procedures (Li et al 2014).…”