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Berries are a rich source of phytochemicals, especially phenolics well known for protective activity against many chronic diseases. Berries also contain a complex mixture of volatile compounds that are responsible for the unique aromas of berries. However, there is very limited information on the composition and potential health benefits of berry volatiles. In this study, we isolated phenolic and volatile fractions from six common berries and characterized them by HPLC/HPLC-MS and GC/GC-MS, respectively. Berry phenolic and volatile fractions were evaluated for an anti-inflammatory effect using lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells by measuring levels of pro-inflammatory cytokines and the nuclear factor-kappa B (NF-κB) signaling pathway. Results showed that LPS-induced excessive production of nitric oxide (NO), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), which were inhibited by berry phenolic and volatile extracts. Moreover, berry phenolic and volatile extracts reduced the nuclear translocation of NF-κB by blocking the phosphorylation of p65 and degradation of IκBα. These findings showed that berry volatiles from six berries had comparable anti-inflammatory effects to berry phenolics through the suppression of pro-inflammatory mediators and cytokines expression via NF-κB down-regulation, despite being present in the fruit at a lower concentration.

Abstract. BACKGROUND:Many brightly colored fruits and vegetables owe their pigmentation and beneficial health effects to anthocyanins. Unfortunately, anthocyanins in the presence of ascorbic acid are readily degraded over juice processing and storage, which adversely affects color stability and potential health benefits. OBJECTIVE: This project focused on the effect of ascorbic acid as a catalyst in anthocyanin degradation. METHODS:The project involved searching for novel pigmented compounds in a simple model system composed of the most common anthocyanin cyanidin-3-O-␤-glucoside and ascorbic acid, and a second model system consisting of blackberry extract supplemented with ascorbic acid. Degradation products were identified by HPLC-PDA and HPLC-MS. ESR was used to monitor hydroxyl radical formation in the model systems. RESULTS: Over 72 hours at ambient temperature, 67% of cyanidin-3-O-␤-glucoside was lost in the model system during which time an unknown pigmented compound was formed. The unknown compound was also formed in a more complex model system consisting of blackberry extract and ascorbic acid. HPLC with PDA monitoring at 510 nm was used to detect a novel compound and HPLC-ESI-MS 3 allowed a proposed structure to be built based on the fragmentation patterns. The unknown structure formed via oxidation of cyanidin 3-O-␤-glucoside by ascorbic acid was identified as 6-hydroxy-cyanidin-3-O-␤-glucoside. The mechanism was substantiated with malvidin-3-O-␤-glucoside and ascorbic acid, which produced a hydroxylated malvidin-3-O-␤-glucoside. Production of hydroxyl radical in the base and blackberry model systems was confirmed by ESR. CONCLUSIONS: We propose that the pigmented compound is formed from hydroxyl radicals via the Haber-Weiss reaction. The addition of food grade hydroxyl radical scavengers to juices may be a viable treatment to prevent ascorbic acid-catalyzed degradation of anthocyanins.

Blackberry anthocyanins provide attractive color and antioxidant activity. However, anthocyanins degrade during juice processing and storage, so maintaining high anthocyanin concentrations in berry juices may lead to greater antioxidant and health benefits for the consumer. This study evaluated potential additives to stabilize anthocyanins during blackberry juice storage. The anthocyanin stabilizing agents used were: glutathione, galacturonic acid, diethylenetriaminepentaacetic acid and tannic acid, which were added at a level of 500 mg L. Juice anthocyanin, flavonol, and ellagitannin content and percent polymeric color were measured over five weeks of accelerated storage at 30 °C. Glutathione had the greatest protective effect on total anthocyanins and polymeric color. Therefore a second study was performed with glutathione in combination with lipoic and ascorbic acids in an effort to use antioxidant recycling to achieve a synergistic effect. However, the antioxidant recycling system had no protective effect relative to glutathione alone. Glutathione appears to be a promising blackberry juice additive to protect against anthocyanin degradation during storage.

Pectin is a soluble fiber with demonstrated health benefits such as the ability to lower blood glucose and cholesterol, increased satiety leading to lower caloric intake and improved insulin resistance. These benefits suggest that pectin may help in prevention and treatment of diseases such as diabetes and obesity. Soybean seed coats, a co‐product of soybean processing, are good source of fiber (pectin) and shows potential as a value‐added product. The objective of this study is to examine the effects of soy pectin on blood glucose and insulin responses. Using a randomized‐crossover design, fifteen healthy men were randomly assigned to two groups (control and soy pectin). Fasting finger‐stick blood samples were collected at 15 minutes before and 0, 15, 30, 45, 60, 75, 90, 120, and 180 minutes after consumption of control solution with added soy pectin or a control solution. Although no specific time interval was significantly different, a reduction in plasma glucose and insulin concentrations was observed. Compared with the control, mean glucose iAUC (incremental area under the curve) for the soy pectin treatment was lowered by ~13.2% from 5059 + 506 to 4390 + 387 µU (~3 h) L‐1. Results suggest soy pectin has a potential for use as a functional food ingredient to improve human health. Funding provided by Arkansas Soybean Promotion Board is greatly appreciated.

Red radish anthocyanins are relatively stable due to the acylation of anthocyanins with organic and phenolic acid moieties. The objective of this study was to create and identify a novel ethyl-bridged acylated anthocyanin with a stable violet color from red radishes in the presence of acetaldehyde and catechin. After incubation at ambient temperature for one week at 21 °C the reaction mixture with acetaldehyde and catechin turned from bright red to a vivid purple color. The newly formed compounds were tentatively identified with liquid chromatography-electrospray ionization-mass spectrometry. Color stability (CIE L*C*h) was monitored over six months at 21 °C and anthocyanin stability was evaluated by HPLC. Next, radishes were fermented by Zymomonas mobilis, a high acetaldehyde producing bacteria. Natural sources of catechin were used to replace the catechin standard, but the same purple color did not appear with the addition of cocoa powder or fava beans. The ethyliden-bridged radish anthocyanins possess excellent color stability and could serve as a natural food colorant.

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