Effect of mixing time, freeze-drying and baking on phenolics, anthocyanins and antioxidant capacity of raspberry juice during processing of muffins

Among the phytonutrients, anthocyanins have been extensively studied because of their antioxidant power, the characteristic supposedly responsible for their capacity for chronic disease prevention. Anthocyanins can also be synthesized in maize even though in Europe the colourless varieties have always been preferred. The aim of this study was to develop and characterize a new polenta variety of maize rich in anthocyanins, bred by a recurrent selection scheme, to increase the antioxidant power of this food. The recurrent selection was based on the anthocyanin content and other specific traits of the kernel. The coloured polenta obtained was analysed by TLC (Thin Layer Chromatography) analysis and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging ability, before and after cooking. The results obtained showed that even though cooking reduced the anthocyanin content by about 22%, the remaining anthocyanins exhibited twofolds higher antioxidant capacity, expressed as ARP (antiradical power) using acetone/water extraction buffer in DPPH assay, compared to the colourless control. Furthermore, our data showed that the anthocyanin content did not alter the taste of the coloured polenta.

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“…) and also in the total phenols of baked muffins enriched with red raspberry juice (Rosales‐Soto et al. ).…”

Section: Discussionmentioning

confidence: 99%

Development and study of a maize cultivar rich in anthocyanins: coloured polenta, a new functional food

et al. 2014

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“…The combination of infrared drying and microwave drying has been applied in the dehydration of peach (Wang and Sheng 2006). Convective drying (Ljubinko et al 2012), freeze drying (Sablani et al 2011;Rosales-Soto et al 2012) and microwave vacuum drying (Bórquez et al 2010;Yanqiu et al 2013) are found to be used for raspberry dehydration. However, the infrared radiation and microwave vacuum combined drying (IR-MVD) characteristics and quality of raspberry were never reported.…”

Section: Introductionmentioning

confidence: 99%

Infrared Radiation and Microwave Vacuum Combined Drying Kinetics and Quality of Raspberry

Chen

et al. 2015

J Food Process Engineering

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Infrared radiation and microwave vacuum combined drying (IR-MVD) kinetics and quality of raspberries under different microwave powers (400, 600, 800 W) and vacuum pressures (45, 65, 85 kPa) were investigated. Drying processes were found to be well fitted with Henderson and Pabis model for infrared radiation drying (IRD) and Midilli model for microwave vacuum drying (MVD). Drying time was reduced and moisture effective diffusivity (Deff) was promoted with the increase of microwave power. In terms of vacuum pressure, the most rapid moisture diffusion was noted at 65 kPa. IR-MVD led to brighter products but caused decreases in redness values. The highest a* value (11.33), lowest ΔE value (12.66) and largest h°value (9.01) were noted at the condition of 600 W and 85 kPa. No significant difference was found between crispness values for different IR-MVD conditions. Good rehydration property was obtained under the strongest microwave power and the highest vacuum pressure. Additionally, anthocyanin losses happened and antioxidant activity declined during dehydration. The highest anthocyanin retention (66.24%) was obtained at the condition of 600 W and 65 kPa. The maximum retention of the antioxidant capacity determined by ABTS (2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)), DPPH (1,1-diphenyl-2-picrylhydrazyl) and FRAP (ferric reducing ability of plasma) were 72.12, 75.03 and 55.19%, respectively, at the vacuum pressure of 85 kPa and microwave power of 600 W. By comparison, the time IR-MVD used was only 55.56% of IRD; moreover, raspberries dried by IR-MVD showed 25.63% higher rehydration ratio, 2.4 times higher crispness value, 17.55% higher anthocyanin retention and 21.21% higher DPPH radical-scavenging activity than IRD. PRACTICAL APPLICATIONSFresh raspberries, with juicy and soft texture, are highly perishable fruits and are frequently dehydrated so that they are available to consumers throughout the year. Dehydrated raspberries are also desirable as ingredients in dairy and bakery products. Infrared radiation and microwave vacuum combined drying (IR-MVD) was adopted for raspberry dehydration in order to achieve dehydrated products with high drying efficiency and good quality. The effects of the drying parameters, including microwave powers and vacuum pressures, on the drying characteristics and quality of raspberries were studied. The results showed that drying under high microwave power increased drying rate. High vacuum pressure promoted better product color and rehydration property as well as anthocyanin preservation and antioxidant activity. IR-MVD was proved to improve the rehydration properties, anthocyanin retention and antioxidant capacity of products in comparison with infrared radiation drying alone. Therefore, IR-MVD is a promising method to promote drying efficiency and protect the quality of raspberries. The results of this study contribute to the technological application of IR-MVD for raspberry dehydration and preservation. Journal of Food Process Engineering

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“…The improved antioxidant properties of the CP‐enriched muffins were presumably due to the incorporation of compounds with strong antioxidant activity – mainly anthocyanins, where cyanidin‐3‐ O ‐rutinoside was predominant. Comparing the stability of anthocyanin compounds in baked muffins, Rosales‐Soto et al observed extremely small concentrations of these bioactive compounds in muffins enriched with raspberry juice, as compared to raspberry juice alone. These authors also pointed that this may result from poor stability and thermal degradation of the anthocyanins during baking.…”

Section: Discussionmentioning

confidence: 99%

“…Muffins rank third in popularity among breakfast products and attract a broad range of consumers . However, foodstuffs with high energy density and low nutrient values, such as muffins, cannot be recommended from a nutritional point of view to be eaten every day.…”

Section: Introductionmentioning

confidence: 99%

“…4 Muffins rank third in popularity among breakfast products and attract a broad range of consumers. 5 However, foodstuffs with high energy density and low nutrient values, such as muffins, cannot be recommended from a nutritional point of view to be eaten every day. Manipulating the satiating effect of this food could thus prove beneficial in controlling food intake and therefore potentially also in regulating body weight.…”

Section: Introductionmentioning

confidence: 99%

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The effects of muffins enriched with sour cherry pomace on acceptability, glycemic response, satiety and energy intake: a randomized crossover trial

et al. 2015

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Effect of mixing time, freeze-drying and baking on phenolics, anthocyanins and antioxidant capacity of raspberry juice during processing of muffins

Abstract: Despite the reduction in valuable compounds, muffin is a vehicle for the delivery of these compounds.

Cited by 38 publications

References 48 publications

Development and study of a maize cultivar rich in anthocyanins: coloured polenta, a new functional food

Development and study of a maize cultivar rich in anthocyanins: coloured polenta, a new functional food

Infrared Radiation and Microwave Vacuum Combined Drying Kinetics and Quality of Raspberry

The effects of muffins enriched with sour cherry pomace on acceptability, glycemic response, satiety and energy intake: a randomized crossover trial

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