No abstract

The influence of deep-frying using different oils and temperatures on carotenoid content and physicochemical and sensory characteristics of carrot chips was investigated. Sliced carrots were steam-blanched, cooled, soaked in 0.2% sodium metabisulfite, and deep-fried in canola, palm, or partially hydrogenated soybean oil (PHSO) at 165, 175, or 185 Њ Њ Њ Њ ЊC. Frying temperature, but not oil, significantly (P Ͻ Ͻ Ͻ Ͻ Ͻ 0.05) affected the ␣ ␣ ␣ ␣ ␣-carotene, ␤ ␤ ␤ ␤ ␤-carotene, and total carotenoid contents. Oil type significantly (P Ͻ Ͻ Ͻ Ͻ Ͻ 0.05) influenced all color values. Increasing temperature lowered the redness value, which correlated with decreased carotenoid content, color darkening, and decreased hardness value. Trained panelists detected no differences among oil types in crispness, sweetness, odor, and acceptability. The best carrot-chip product was that fried in PHSO at 165 Њ Њ Њ Њ ЊC.

Carrot slices were subjected to one of the following experiments prior to deep-frying: (A) dehydration/rehydration, (B) soaking in different antioxidants, and (C) fermentation with/without blanching. There were no significant differences (P > or = 0.05) in carotenoid contents among carrot chips treated with/without dehydration. Soaking in sodium metabisulfite resulted in the highest carotenoid content and lightness (L), redness (a), and yellowness (b) values among the antioxidant treatments. Fermentation without blanching significantly decreased (P < 0.05) carotenoid content, vitamin A activity, and fat content. Dehydration and fermentation with blanching significantly increased (P < 0.05) the lightness (L), redness (a), and yellowness (b) values of the chips. Dehydration/rehydration, but not antioxidant and fermentation, significantly decreased (P < 0.05) the water activity of the chips. The textural values of carrot chips prepared using sodium metabisulfite, without dehydration and without fermentation, were the lowest among other treatments which suggests the crispiest. Carrot chips prepared using sodium metabisulfite, without dehydration and without fermentation, had the highest carotenoid content and retention, and the highest overall acceptability score.

The aim of this study was to investigate antioxidant activity, total phenolic compounds and flavonoids of propolis from three provinces of Indonesia with two methods of extraction. Stingless bee propolis from Banten, South Kalimantan, and South Sulawesi was prepared through ultrasound-assisted extraction with water and ethanol solvents, separately. Antioxidant activity was measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Total phenolic and flavonoid contents were analyzed by Folin-Ciocalteu colorimetric and aluminum chloride (AlCl3) methods, respectively. The result showed that the antioxidant activity expressed as IC50 of Indonesian propolis ranged from 452.52 to 1027.29 mg/L. Ethanol extracts showed higher antioxidant activity than water extracts. Total phenolic and flavonoids content detected in the samples ranged from 10.00 to 28.65 mg/g GAE and 0.76 to 3.39 mg/g QE, respectively. The ethanol extract of propolis from South Kalimantan had the highest total phenolic contents, while that from South Sulawesi possessed the highest total flavonoids.

Deep-fried carrot chips were packaged in layered film (metallized polyester and linear lowdensity polyethylene) pouches under a partial vacuum of <1% O 2 concentration. Packages containing chips were stored in dark chambers at three conditions: 0-1°C, 94-98% relative humidity (r.h.) (A); 22-23°C, 31-45% r.h. (B); and 29-31°C, 89-93% r.h. (C) for 0-5 months. Retention of a-and b-carotene content and vitamin A activity were >82% over 5 months for all conditions. Colour values (L, a, b) were unchanged over 5 months for A and B, but decreased gradually (P < 0.05) for C. No changes in moisture content, fat content, water activity, texture values and sensory values were observed over time for A and B, but changed (P < 0.05) for C. No sensory differences were observed by condition or time in colour. Carrot chips, packaged in partially vacuumed opaque pouches, can be stored for at least 5 months at 0-1°C, 94-98% r.h. or 22-23°C, 31-45% r.h.