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The health‐relevant functionality of fruit extracts from 12 Rubus cultivars was evaluated for potential diabetes and hypertension management. Inhibition of in vitro α‐amylase, α‐glucosidase and angiotensin‐1‐converting enzyme (ACE‐1) activity was evaluated in conjunction with phenolic content and antioxidant activity. Black raspberries, Jewel and MacBlack cultivars, had the highest overall phenolic content and antioxidant activity. Red raspberry cultivars, Nova, Heritage and K81‐6, showed the overall highest α‐amylase inhibition in water and ethanol extracts. Jewel, a black raspberry cultivar, had the lowest α‐amylase inhibitory activity of 40% or lower. Ethanol extracts of all 12 cultivars showed high inhibitory activity (above 85%) against α‐glucosidase. The yellow raspberry, KCB‐1, was the most effective at inhibiting α‐glucosidase in both water and ethanol extracts. Fruit extracts of the yellow raspberries, KCB‐1 and Kiwi Gold, showed the most potential for ACE‐1 inhibition. Jewel and the red raspberry, Caroline, also had good activity against ACE‐1. PRACTICAL APPLICATION The insights from this research provide the biochemical rationale for further in vivo studies based on in vitro enzyme inhibition studies. This structure‐function‐based rationale can help to target specific cultivars of raspberry with specific and uniform phenolic profiles for diet designs targeted for managing early stages of type II diabetes and hypertension. The structure‐function rationale of this in vitro study can also provide the directions for better design of animal and human clinical studies for more precise dietary recommendations for the previously mentioned chronic disease targets.

Transplanting of micropropagated blackberry plugs in the field during late summer and early fall is a common nursery practice for commercial blackberry production. During this field transition, blackberry plants generally experience different stresses in addition to transplanting shock coupled with sudden exposure to low night temperatures in the fall. Improving the stress resilience of field-transplanted blackberry plants by recruiting plant endogenous protective metabolic responses has significant merit. Therefore, the aim of this study was to improve stress resilience of newly transplanted ‘Chester Thornless’ blackberry in the field during fall transition through stimulation of phenolic antioxidant and proline-linked metabolic responses by using bioprocessed chitosan oligosaccharide (COS) as an elicitor treatment. Fourteen-week-old blackberry plugs were transplanted in the field in late July and COS was sprayed weekly in the run-off for a 6-wk period after transplanting. Total soluble phenolic content, total antioxidant activity, total proline content, proline dehydrogenase, and succinate dehydrogenase enzyme activity of blackberry shoots were evaluated weekly during and 1 wk after COS application. Improvement in total soluble phenolic content and antioxidant activity based on 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) free radical scavenging assay was observed in field-transplanted blackberry at 6 and 7 wk with COS elicitation treatment.

K. 2015. Phenolic bioactives from developmental stages of highbush blueberry (Vaccinium corymbosum) for hyperglycemia management using in vitro models. Can. J. Plant Sci. 95: 653Á662. Blueberry is a rich source of soluble phenolics as well as human health relevant antioxidants. Phenolic-linked bioactive functionality of blueberry for type 2 diabetes management was screened during fruit maturation, especially from green to ripening stages using in vitro assays. Green fruit showed the highest total soluble phenolic content, whereas all three developmental stages of blueberry fruit exhibited high total antioxidant activity. Overall, ripe fruit had higher a-amylase and a-glucosidase inhibitory activity than green or green/pink fruit, and showed significant potential to improve glucose metabolism through in vitro assays. High phenolic-linked antioxidant activity along with moderate to high a-amylase and a-glucosidase inhibitory activity in ripe blueberry indicated its potential relevance as part of diet-based prevention and management of early stages of hyperglycemia associated with development of type 2 diabetes. This in vitro screening study provides a biochemical rationale and dietary strategy to develop the right blueberry cultivar and stage of fruit development for further validation in animal and clinical studies.Key words: Antioxidant, bioactive, functionality, highbush blueberry, hyperglycemia, phenolic Cheplick, S., Sarkar, D., Bhowmik, P. et Shetty, K. 2015. De´termination des compose´s phe´noliques bioactifs issus des stades de de´veloppement du bleuet en corymbe (Vaccinium corymbosum) pour la prise en charge de l'hyperglyce´mie au moyen de mode`les in vitro. Can. J. Plant Sci. 95: 653Á662. Le bleuet est une riche source de compose´s phe´noliques solubles ainsi que d'antioxydants pre´sentant un inte´reˆt pour la sante´humaine. On a examine´la bioactivite´des compose´s phe´noliques du bleuet pour le diabe`te de type 2 pendant la maturation du fruit, particulie`rement du fruit vert au fruit muˆr en recourant ad es tests in vitro. Le fruit vert est celui qui pre´sente la plus forte concentration totale de compose´s phe´noliques solubles, alors que les trois stades de de´veloppement illustrent une forte activite´totale en tant qu'antioxydant. Dans l'ensemble, le fruit muˆr inhibe plus la a-amylase et la a-glucosidase que le fruit vert ou rose, et pourrait ame´liorer de fac¸on significative le me´tabolisme du glucose, comme le de´montrent les essais in vitro. La forte activite´anti-oxydation lie´e aux compose´s phe´noliques ainsi que l'inhibition moyenne a`e´leve´e de la a-amylase et de la a-glucosidase des bleuets muˆrs indiquent que ce fruit pourrait pre´senter de l'inte´reˆt à titre pre´ventif dans l'alimentation, mais aussi pour ge´rer les premiers stades de l'hyperglyce´mie associe´e au de´veloppement du diabe`te de type 2. Cette e´tude de controˆle in vitro fournit un motif biochimique et une strate´gie die´te´tique en vue de la cre´ation d'un cultivar approprie´de bleuet et de l'e´tablissement du stade ...

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