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Evdokia Menelaou, Armen Kachatryan, Jack N. Losso, Michael Cavalier, and Don La Bonte

Fresh leaves of 6 sweetpotato (Ipomoea batatas [L.] Lam.) genotypes, `Beauregard', `Bienville', L99–35, L00–8, L01–145, and L01–29, were characterized for lutein. Lutein is a carotenoid capable of delaying blindness-related macular degeneration. The content of lutein in sweetpotato ranged from 0.38 to 0.58 mg·g–1 fresh weight. Beta-carotene separated from lutein on high-pressure liquid chromatograms and when spiked in pure lutein extract did not interfere with lutein separation. High-resolution electro-spray ionization mass spectrometric analysis was used to confirm the presence of lutein in sweetpotato leaves. Stems were also characterized and found not to contain lutein. Our results showed that sweetpotato leaves are an excellent source of dietary lutein and surpass levels found in leafy crucifers. Leaves of sweetpotato and a related species are human food in some countries and may be a major source of lutein for commercial purposes.

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Rebecca E. Stein-Chisholm, John W. Finley, Jack N. Losso, and John C. Beaulieu

Juice production is a multibillion dollar industry and an economical way to use fruit past seasonal harvests. To evaluate how production steps influence not-from-concentrate (NFC) blueberry (Vaccinium sp.) juice recovery, bench top and pilot scale experiments were performed. In bench-top, southern highbush (SHB) blueberry (Vaccinium darrowii × Vaccinium corymbosum) and rabbiteye blueberry (RAB) (Vaccinium ashei) were pressed at varying temperatures. Press treatments included ambient temperature, frozen then thawed, and frozen then heated berries. In addition, two commercial pectinase enzymes were evaluated. Three batches were pressed and average juice recovery was calculated. The highest average free juice recovery (68.8% ± 1.1%) was attained by heating frozen berries and treating with enzyme. Comparing berry species pressed, SHB blueberries produced significantly more juice than RABs. There were no significant differences between enzymes used between berry species. Using this preliminary data, the optimum juice recovery method was then transferred to pilot scale processing. RABs were heated and treated with enzyme then pressed. Free juice recovery from the pilot scale was 74.0% ± 1.0%. Total juice recovery was calculated to be 87% ± 0.6%. With this information, further refinement of juice processes could increase juice production output for small-scale producers and expand local outlets for growers to market their crops as well as create new opportunities for growth in the fresh juice market segment.