Effects of Aromatic Herb Flavoring on Carotenoids and Volatile Compounds in Edible Oil From Blue Sweet Lupin (Lupinus angustifolius)

Abstract

This study investigates the carotenoid and volatile compositions of one sample of lupin oil (Lupinus angustifolius) and five samples of lupin oil flavored with aromatic herbs, namely, basil, chives, rosemary, sage, and thyme. Flavored oils are obtained by macerating lupin oil with the herbs for 15 days, in the dark at 15 ± 1 °C. Overall 11 carotenoids are identified by HPLC‐DAD‐MS‐(APCI). (all‐E)‐Lutein and β‐carotene are the most abundant. Thyme flavored oil results the richest in carotenoids, with a cumulative carotenoid content of 195 ± 13 μg mL−1. Volatile organic compounds are detected by HS‐SPME‐GC/MS analysis. Overall, 50 aroma compounds are determined, with alcohols, furans, and terpenoids being the most abundant classes. Chives flavored oil is the only sample to provide organosulfur compounds. Qualitatively, terpenoids are responsible for great differences among the samples, since unique terpenoid profiles are observed, for example, isoterpinolene is detected only in sage flavored oil, β‐myrcene in rosemary flavored oil, and thymol in thyme flavored oil. The relative odor activity value (ROAV) is determined and employed to evaluate the contributions of the single compounds to the overall odor. The compounds with the greatest odor activity are 3‐hexen‐1‐ol, hexanal, α‐pinene, eucalyptol, and 2‐pentylfuran.Practical Applications: Aromatic herbs have been traditionally used to enhance the flavor of food. The effects of herbs addition on lupin products has not been investigated yet. Additionally, this is the first study that explores some quality characteristics of commercial lupin oil. Data indicate that the maceration of lupin oil with aromatic herbs has limited effects on the content of total carotenoids, nonetheless, it modifies markedly the composition and relative proportions of the volatile organic compounds, and likely the overall aromas. Consumers are generally not familiar with the culinary use of lupin oil, nevertheless, the aromatization with herbs could increase its use. Lupin oil results rich in carotenoids. This is useful information for the production of functional products with healthy properties. Lupin oil can be recommended as a carotenoid‐rich product and as an alternative to more traditional table oils. Data from this study can contribute to the economic valorization of lupin oil.This study assesses the effects of the maceration of lupin oil with aromatic herbs, e.g., basil, chives, rosemary, sage, and thyme on the content of volatile organic compounds, and investigates the carotenoid profile of the flavored oils. Flavored oils are prepared by macerating lupin oil with the herbs (6% w/w) for 15 days, in the dark at 15 ± 1°C. Plain lupin oil and basil, chives, and thyme flavored oils are relatively rich in 2‐pentylfuran, whereas rosemary flavored oil is abundant in α‐pinene. (all‐E)‐Lutein is the predominant carotenoid in all the experimental oils, followed by β‐carotene.