This study analysed fruits of cranberry cultivars: Ben Lear, Bergman, Early Richard, Pilgrim and Stevens and compared them with wild-grown cranberry fruits. The fruits were characterised in terms of dimensions, colour, content of total phenolic compounds, flavonoids, proanthocyanidins and anthocyanins, and hydroxyl radical and trypsin inhibition activities. It was shown that the wild-grown cranberry fruits were characterised by much smaller dimensions and redder colour than fruits of the cranberry cultivars. The most phenolic compounds were found in the Early Richard fruits (357.6 mg/100 g fw), and they showed the highest antitrypsin activity. The highest anthocyanin content (60.6 mg/100 g fw) was determined in the Pilgrim fruits, while the Ben Lear fruits were the richest source of proanthocyanidins (27.9 mg/100 g fw). The antioxidant activity was correlated with the content of phenolic compounds, flavonoids and proanthocyanidins, while the antitrypsin activity was correlated with phenolic compounds and anthocyanin contents.

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The study assesses the antioxidant activity (AA), carotenoid profile and total phenolic content (TPC) of carrot juices obtained from three different varieties (black, orange and yellow) and prepared using high- (HSJ) and low-speed juicer (LSJ). The AA assessment was carried out using four assays (DPPH, ABTS, PCL ACW and PCL ACL). The content of carotenoids was conducted by high performance liquid chromatography equipped with a diode array detector (HPLC-DAD) method, while the total phenolic content by the spectrophotometric method. It was shown that orange carrot juices contain more carotenoids than yellow and black carrot juices, approximately ten and three times more, respectively. The total carotenoid content in orange carrot juice made by the HSJ was higher (by over 11%) compared to juice prepared by the LSJ. The highest total phenolic content was noticed in black carrot juices, while the lowest in orange carrot juices. In black carrot juices, a higher range of TPC was found in juices made by HSJ, while in the case of the orange and yellow carrots, the highest content of TPC was detected in juices prepared by the LSJ. AA of the juices was highly dependent on the carrot variety, juice extraction method. The most assays confirmed the highest AA values in black carrot juices. Furthermore, it was shown that the HSJ method is more preferred to obtain orange and yellow carrot juices with higher antioxidant properties, while the LSJ method is more suitable for black carrot juice extraction.

Broccoli and green asparagus were cooked using boiling water, steam, microwave oven and combi oven with overheated steam and combination of hot air with overheated steam (only broccoli). Vegetables were analysed for chlorophylls a and b, carotenoids, total polyphenols, antioxidant activity, colour parameters and sensory properties. Cooking in the combi oven with overheated steam was an effective method to achieve the highest levels of polyphenols and antioxidant activity, but it negatively influenced the contents of chlorophylls in both vegetables and carotenoids in asparagus. Boiling and cooking in the combi oven with overheated steam or hot air and steam ensured the best and comparable sensory properties of broccoli. Asparagus showed a lower susceptibility to heat treatments than broccoli as none of the treatments applied caused significant differences in colour redness and yellowness, polyphenol content and sensory properties of this vegetable.

Borowski J., Narwojsz J., Borowska E.J., Majewska K. (2015): The effect of thermal processing on sensory properties, texture attributes, and pectic changes in broccoli. Czech J. Food Sci., 33: 254-260.Broccoli cooked in a convection steam oven at different temperatures and times was evaluated and compared with broccoli boiled in water. Broccoli was subjected to a sensory analysis, and its texture parameters were determined instrumentally. The effect of various thermal processing methods on pectic compounds was analysed. The application of different cooking methods led to significant variations in the analysed attributes. The majority of the observed differences were statistically significant (P < 0.05). Broccoli cooked in a convection steam oven at 125°C with 90% steam saturation for 8 min was characterised by the most desirable sensory attributes and scored 8.5 on a 10-cm unstructured line scale. The same samples had the greatest firmness and the highest protopectin content (72.9%). Broccoli boiled in water scored the lowest number of points, and it had the lowest protopectin content (51%).