Children's liking and wanting of foods vary over multiple bites/sips of consumption: A case study of foods containing wild blueberry powder in the amounts targeted to deliver bioactive phytonutrients for children.

To encourage children to frequently consume wild blueberries as part of their dietary patterns, incorporating blueberry powder into specific foods may be an effective strategy. Thus, it is important to determine appropriate types of food products that both minimize food processing-induced loss of beneficial components of blueberries (e.g., anthocyanins) and satisfy at the same time both nutritional and sensory aspects. For clinical studies assessing the health benefits of blueberry-containing food samples, it would be important to ensure children consume the entire portion of the test samples. This study, therefore, aimed at determining how sensory acceptability (liking) and psychological reward (wanting) of wild blueberry-based foods vary over multiple steps of ad libitum consumption: appearance, first bite/sip, half bite/sip, and full consumption. Five different types of foods containing the targeted amount of wild blueberry powder were prepared for sensory testing (oatmeal bar, beverage, ice pop, gummy, and cookie), and the residual amounts of total anthocyanin and chlorogenic acid were measured to confirm levels targeted to deliver bioactive amounts of these phytochemicals. Results showed that while overall liking and desire to eat did not differ among the five samples at the appearance and first bite/sip steps, they differed significantly at the end of consumption. Although children liked and wanted to consume the cookies more when compared to beverages, ice pops, and/or gummies, total anthocyanin contents were lower in cookies and gummies than in wild blueberry powder, beverage, and ice pop samples. Notably, the oatmeal bars with significant amounts of total anthocyanin and chlorogenic acid did not significantly differ from the cookies with respect to overall liking, desire to eat, and the amount consumed. In conclusion, this study shows that sensory evaluation using multiple bites/sips of ad libitum food consumption, along with a measurement of beneficial compounds, is efficient in determining appropriate vehicles for clinical studies of wild blueberry-containing foods.

Recent Research on the Health Benefits of Blueberries and Their Anthocyanins.

Awareness of the human health benefits of blueberries is underpinned by a growing body of positive scientific evidence from human observational and clinical research, plus mechanistic research using animal and in vitro models. Blueberries contain a large number of phytochemicals, including abundant anthocyanin pigments. Of their various phytochemicals, anthocyanins probably make the greatest impact on blueberry health functionality. Epidemiological studies associate regular, moderate intake of blueberries and/or anthocyanins with reduced risk of cardiovascular disease, death, and type 2 diabetes, and with improved weight maintenance and neuroprotection. These findings are supported by biomarker-based evidence from human clinical studies. Among the more important healthful aspects of blueberries are their anti-inflammatory and antioxidant actions and their beneficial effects on vascular and glucoregulatory function. Blueberry phytochemicals may affect gastrointestinal microflora and contribute to host health. These aspects have implications in degenerative diseases and conditions as well as the aging process. More evidence, and particularly human clinical evidence, is needed to better understand the potential for anthocyanin-rich blueberries to benefit public health. However, it is widely agreed that the regular consumption of tasty, ripe blueberries can be unconditionally recommended.

Berry polyphenols metabolism and impact on human gut microbiota and health.

Berries are rich in phenolic compounds such as phenolic acids, flavonols and anthocyanins. These molecules are often reported as being responsible for the health effects attributed to berries. However, their poor bioavailability, mostly influenced by their complex chemical structures, raises the question of their actual direct impact on health. The products of their metabolization, however, may be the most bioactive compounds due to their ability to enter the blood circulation and reach the organs. The main site of metabolization of the complex polyphenols to smaller phenolic compounds is the gut through the action of microorganisms, and reciprocally polyphenols and their metabolites can also modulate the microbial populations. In healthy subjects, these modulations generally lead to an increase in Bifidobacterium, Lactobacillus and Akkermansia, therefore suggesting a prebiotic-like effect of the berries or their compounds. Finally, berries have been demonstrated to alleviate symptoms of gut inflammation through the modulation of pro-inflammatory cytokines and have chemopreventive effects towards colon cancer through the regulation of apoptosis, cell proliferation and angiogenesis. This review recapitulates the knowledge available on the interactions between berries polyphenols, gut microbiota and gut health and identifies knowledge gaps for future research.

Changes in polyphenolics during maturation of Java plum (Syzygium cumini Lam.).

Java plum (Syzygium cumini Lam.) is a rich source of polyphenolics with many purported health benefits, but the effect of maturation on polyphenolic content is unknown. Freeze-dried samples of Java plum from seven different maturity stages were analyzed for anthocyanin, flavonol, flavanonol and hydrolysable tannin composition by HPLC. Anthocyanins were first detected at the green-pink stage of maturity and increased throughout maturation with the largest increase occurring from the dark purple to black stages of maturation. Levels of gallotannins, ellagitannins, flavonols, gallic acid and ellagic acid were highest at early stages of maturation and decreased as the fruit ripened. For production of antioxidant-rich nutraceutical ingredients, fruit should be harvested immature to obtain extracts rich in hydrolysable tannins and flavonols. The exceptional anthocyanin content of black fruit may prove useful as a source of a natural colorant.

Stabilization of anthocyanins in blackberry juice by glutathione fortification.

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-1. 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.

Urinary excretion of phenolic acids in rats fed cranberry, blueberry, or black raspberry powder.

Dietary polyphenolics can be converted into smaller phenolic acids (PA) by microorganisms in the colon and may contribute to health benefits associated with the parent polyphenolics. Urinary excretion of 18 PA and their conjugates was studied, using HPLC-MS/MS, in rats fed AIN93G-based diets containing 5% (dry weight basis) of either cranberry (CB), blueberry (BB), or black raspberry (BRB). Hippuric, 4-hydroxyphenylacetic, 3-methoxy-4-hydroxyphenylacetic, and 4-hydroxybenzoic acids were excreted in greatest quantity in the urine over a 24 h period in all diets. Primary PA excreted in the berry diets were 4-hydroxycinnamic acid for CB; chlorogenic, ferulic, and 3,4-dihydroxycinnamic acids for BB; and 3-hydroxyphenylpropionic, 3-hydroxybenzoic, and 3-hydroxycinnamic acids for BRB. PA were present in conjugated form with cinnamic acid derivatives being 50-70% and phenylacetic acid derivatives conjugated <10%. Conjugated, and not just the free, PA are significant contributors to total urinary excretion.

Changes in chokeberry (Aronia melanocarpa L.) polyphenols during juice processing and storage.

Chokeberries are an excellent source of polyphenols, but their fate during juice processing and storage is unknown. The stability of anthocyanins, total proanthocyanidins, hydroxycinnamic acids, and flavonols at various stages of juice processing and over 6 months of storage at 25 °C was determined. Flavonols, total proanthocyanidins, and hydroxycinnamic acids were retained in the juice to a greater extent than anthocyanins, with losses mostly due to removal of seeds and skins following pressing. Anthocyanins were extensively degraded by thermal treatments during which time levels of protocatechuic acid and phloroglucinaldehyde increased, and additional losses occurred following pressing. Flavonols, total proanthocyanidins, and hydroxycinnamic acids were well retained in juices stored for 6 months at 25 °C, whereas anthocyanins declined linearly. Anthocyanin losses during storage were paralleled by increased polymeric color values, indicating that the small amounts of anthocyanins remaining were present in large part in polymeric forms.

Improved stability of chokeberry juice anthocyanins by ß-cyclodextrin addition and refrigeration.

Chokeberry anthocyanins are susceptible to degradation during processing and storage of processed products. This study determined the effects of three pH levels (2.8, 3.2, and 3.6) and four ß-cyclodextrin (BCD) concentrations (0, 0.5, 1, and 3%) alone and in combination on the stability of chokeberry juice anthocyanins before and after pasteurization and over 8 months of storage at 4 and 25 °C. Lowering the pH from 3.6 to 2.8 in the absence of BCD provided marginal protection against anthocyanin losses during processing and storage. Addition of 3% BCD at the natural chokeberry pH of 3.6 resulted in excellent protection of anthocyanins, with 81 and 95% retentions after 8 months of storage at 25 and 4 °C, respectively. The protective effect of BCD was lessened with concentrations <3% and reduction in pH, indicating changes in anthocyanin structure play an important role in BCD stabilization of anthocyanins.

Effect of dietary blueberry pomace on selected metabolic factors associated with high fructose feeding in growing Sprague-Dawley rats.

An experiment was conducted to study the protective effect of feeding extruded and unextruded blueberry pomace (BBP) on selected metabolic parameters associated with metabolic syndrome in a model of high fructose (HF)-fed growing Sprague-Dawley rats. Treatments were as follows: (1) control (modified AIN-based diet); (2) HF diet (AIN diet with 58% fructose); (3) HF diet with 1.5% unextruded BBP; (4) HF diet with 1.5% extruded BBP; (5) HF diet with 3% unextruded BBP; and (6) HF diet with 3% extruded BBP. Compared with the control, HF feeding increased fasting plasma insulin and fasting and postprandial plasma triglycerides as well as homeostatic scores of insulin resistance and ß-cell function, but not weight gain, diet intake and efficiency, abdominal fat, oral glucose tolerance, and fasting and postprandial plasma glucose, cholesterol, and leptin levels. Inclusion of unextruded or extruded BBP was effective in minimizing or ameliorating the fructose-induced metabolic anomalies, except postprandial plasma triglycerides, especially at 3% of the diet. In addition, unextruded or extruded BBP at 3% of the diet was also able to reduce plasma cholesterol and abdominal fat relative to the HF control, which may impart additional health benefits. Compared with the control, inclusion of unextruded or extruded BBP at both 1.5% and 3% resulted in lower total fat weight, and animals fed a diet supplemented with 3% unextruded BBP in fasting state or 3% unextruded BBP in fed state had lower leptin levels than the control. This is the first study demonstrating the beneficial effects of feeding blueberry pomace on health.

Design and optimization of a semicontinuous hot-cold extraction of polyphenols from grape pomace.

Grape pomace contains appreciable amounts of polyphenolic compounds such as anthocyanins and procyanidins which can be recovered for use as food supplements. The extraction of these polyphenols from the pomace is usually accomplished at slightly elevated temperatures, frequently employing hydroethanolic solvents. Due to governmental regulations and the cost involved in using ethanol as a solvent, as well as the loss in polyphenolics due to thermal degradation, improved extraction techniques are required. In this study, a semicontinuous extraction apparatus employing only water was developed to maximize the recovery of anthocyanins and procyanidins from red grape pomace (Vitis vinifera). Water is preheated prior to its entry to the extraction cell containing the grape pomace sample, where it is allowed to then flow continuously through the unheated extraction vessel prior to its collection at ambient conditions. Extraction variables that impacted the polyphenolic recovery included pomace moisture content (crude or dried), sample mass, water flow rate, and extraction temperature. A response surface method was used to analyze the results from the extraction, and the optimal conditions were found to be 140 °C and 9 mL/min water flow rate. These conditions can produce an extract containing 130 mg/100 g DW of anthocyanins and 2077 mg/100 g DW of procyanidins. Higher yields of polyphenolics were observed using crude (wet) rather than dried pomace, hence avoiding the need to dry the pomace prior to extraction. The described semicontinuous extraction method using only water as the extraction solvent under subcritical conditions allowed the efficient extraction of polyphenols from red grape pomace without the attendant loss of polyphenolic content due to having to heat the extraction vessel prior to commencement of extraction.

Processing and storage effect on berry polyphenols: challenges and implications for bioactive properties.

Anthocyanins and tannins in blueberries, blackberries and black raspberries are susceptible to degradation during processing, with juices showing the greatest losses due to physical removal of skins and seeds. Anthocyanins and procyanidins are also degraded in processed products stored at ambient temperature with losses accompanied by increased polymeric pigments (PPs). Using chokeberry as a model, formation of PPs occurred in both pasteurized and aged juices and pasteurized juice contained a greater proportion of low molecular weight PPs than aged juice, while aged juice contained a greater proportion of higher molecular PPs. Formation of PP accounts for some of the losses of anthocyanins and procyanidins during processing and storage, but the complete fate of anthocyanins remains unclear. In this review we highlight the steps in processing where significant losses of polyphenols occur, and discuss potential mechanisms responsible for losses, methods to mitigate losses, and implications on bioactive properties.

The blackberry fruit: a review on its composition and chemistry, metabolism and bioavailability, and health benefits.

Blackberry (Rubus sp.) fruit contains high levels of anthocyanins and other phenolic compounds, mainly flavonols and ellagitannins, which contribute to its high antioxidant capacity and other biological activities. Blackberry phenolic composition and concentrations are known to be influenced by genetics, growing conditions, and maturation. Despite the current knowledge of their chemistry, research specific to blackberry phenolic compounds' health benefits, metabolism, bioavailability, and mechanism by which they confer health benefits is scarce. Blackberry phenolic compounds have protective effects on age-related neurodegenerative diseases and bone loss in vivo and can inhibit low-density lipoprotein and liposomal oxidation in vitro. Blackberry extracts have also exerted antimutagenic effects in vitro and in vivo by modifying cell signaling pathways and suppressing tumor promotion factors. However, the antiobesity, antidiabetic, antimicrobial, and anti-inflammatory properties of blackberry phenolic compounds need investigation. Similarly, studies that elucidate the in vivo physiologically effective concentrations of blackberry phenolic compounds are necessary.

Effect of feeding grape pomace on selected metabolic parameters associated with high fructose feeding in growing Sprague-Dawley rats.

The effect of feeding grape pomace on certain metabolic parameters associated with high fructose (HF) feeding was studied. Forty male growing Sprague-Dawley rats were randomly assigned into groups: (1) control; (2) HF; (3) HF with low-level (1.5% of diet) grape pomace (HF+LP), and (4) HF with high-level (5.0% of diet) grape pomace (HF+HP). The HF+LP and HF+HP diets provided 115 and 218 mg of procyanidins/kg, respectively. Compared with the controls, HF-fed animals consumed less and were smaller, whereas animals in the HF+LP and HF+HP groups were in between. A similar trend was observed for abdominal fat and abdominal fat as a percentage of body weight. No change in heart or kidney weight occurred. Liver weight as a percentage of body weight was higher for animals when fructose was included in the diet compared with those on control diet, and inclusion of grape pomace had no effect. Fasting plasma glucose, insulin, and triglyceride levels tended to be higher in animals fed HF diet, and grape pomace reduced their levels to values similar to the control animals. Compared with control animals, HF-fed animals had higher weekly postprandial plasma triglycerides, which were reduced by feeding grape pomace, but no change in plasma cholesterol was observed. Glucose intolerance was observed in animals fed HF diet and was accompanied by a 25% increase in homeostatic model assessment (HOMA) of insulin resistance. Inclusion of grape pomace increased glucose tolerance and insulin sensitivity. No significant change (P>.1) in HOMA of ß-cell function or Quantitative Insulin-Sensitivity Check Index was observed. Overall, HF diet did not produce as strong a response of metabolic syndrome as has been shown in the literature. The inclusion of grape pomace in the diet was effective in modulating some aspects of metabolic parameters associated with metabolic syndrome, and the higher level of grape pomace in the diet produced a slightly better response than the lower level.

Impact of different stages of juice processing on the anthocyanin, flavonol, and procyanidin contents of cranberries.

Juice is the most common form in which cranberries are consumed; however there is limited information on the changes of polyphenolic content of the berries during juice processing. This study investigated the effects of three different pretreatments (grinding plus blanching; only grinding; only blanching) for cranberry juice processing on the concentrations of anthocyanins, flavonols, and procyanidins throughout processing. Flavonols and procyanidins were retained in the juice to a greater extent than anthocyanins, and pressing resulted in the most significant losses in polyphenolics due to removal of the seeds and skins. Flavonol aglycones were formed during processing as a result of heat treatment. Drying of cranberry pomace resulted in increased extraction of flavonols and procyanidin oligomers but lower extraction of polymeric procyanidins. The results indicate that cranberry polyphenolics are relatively stable during processing compared to other berries; however, more work is needed to determine their fate during storage of juices.

Processing and storage effects on the ellagitannin composition of processed blackberry products.

Changes in blackberry ellagitannin composition in response to juicing (clarified and nonclarified), pureeing, canning (in water or syrup), and freezing as well as changes in processed products during 6 months of storage were investigated. Canning, pureeing, and freezing had little effect on ellagitannins, but processing berries into nonclarified and clarified juices resulted in total ellagitannin losses of 70 and 82%, respectively, due to removal of ellagitannin-rich seeds in the presscake. Minimal changes in total ellagitannin content were observed during storage of thermally processed products, but compositional changes indicative of ellagitannin depolymerization were apparent. The ellagitannin content and composition of frozen berries remained stable over 6 months of storage. Ellagitannins are well retained in canned, pureed, and frozen blackberries, but methods are needed to prevent losses during juice processing and/or exploit the ellagitannin-rich coproducts.

Urinary excretion of (Epi)catechins in rats fed different berries or berry products.

(Epi)catechins are associated with many health benefits in humans. However, their bioavailability, excretory pattern, and extent of conjugation in animals fed different sources or levels in the diet are not well documented. Two experiments were conducted to investigate the urinary excretion of (epi)catechins after feeding of different types of berries or different levels of the same berry source to rats. Experiment 1 investigated the effects of feeding a commercially available concentrated cranberry powder (CCP) at three different levels, 3.3, 6.6, and 33 g/kg of diet, whereas experiment 2 investigated the effect of feeding freeze-dried whole cranberry (CB), blueberry (BB), or black raspberry (BRB) powder at 50 g/kg of diet. Both experiments had an AIN-93-based control and a high-fructose diet (53-65% of the diet) to which was added three levels of CCP in experiment 1 and CB, BB, and BRB in experiment 2. (Epi)catechins were excreted as free and conjugated in both intact and methylated forms. Excretion of conjugated (epi)catechins was as high as 60% of the total consumed in some cases. A majority of both catechins and epicatechins excreted in the urine was in a methylated form. Excretion of epicatechins, including their methylated forms, ranged from 30 to 47% of the ingested amount, whereas that of catechins, including their methylated forms, ranged from 9 to 31%. Urinary excretion of (epi)catechins was dose dependent and increased with the amount of (epi)catechins present in the diet. On the basis of the excretory pattern of (epi)catechins in the urine, data suggested that the bioavailability of epicatechins may be higher than that of catechins and that (epi)catechins may be more available from blueberries compared to cranberries.

Release of bound procyanidins from cranberry pomace by alkaline hydrolysis.

Procyanidins in plant products are present as extractable or unextractable/bound forms. We optimized alkaline hydrolysis conditions to liberate procyanidins and depolymerize polymers from dried cranberry pomace. Alkaline extracts were neutralized (pH 6-7) and then procyanidins were extracted with ethyl acetate and analyzed by normal phase high performance liquid chromatography. Alkaline hydrolysis resulted in an increase in low molecular weight procyanidins, and the increase was greater at higher temperature, short time combinations. The most procyanidins (DP1-DP3) were extracted at 60 degrees C for 15 min with each concentration of NaOH. When compared to conventional extraction using homogenization with acetone/water/acetic acid (70:29.5:0.5 v/v/v), treatment with NaOH increased procyanidin oligomer extraction by 3.8-14.9-fold, with the greatest increase being DP1 (14.9x) and A-type DP2 (8.4x) procyanidins. Alkaline treatment of the residue remaining after conventional extraction resulted in further procyanidin extraction, indicating that procyanidins are not fully extracted by conventional extraction methods.

Purified blueberry anthocyanins and blueberry juice alter development of obesity in mice fed an obesogenic high-fat diet.

Male C57BL/6J mice (25 days of age) were fed either a low-fat diet (10% kcal from fat) (LF) or a high-fat diet (45% kcal from fat) (HF45) for a period of 72 days. Blueberry juice or purified blueberry anthocyanins (0.2 or 1.0 mg/mL) in the drinking water were included in LF or HF45 treatments. Sucrose was added to the drinking water of one treatment to test if the sugars in blueberry juice would affect development of obesity. Total body weights (g) and body fat (%) were higher and body lean tissue (%) was lower in the HF45 fed mice compared to the LF fed mice after 72 days, but in mice fed HF45 diet plus blueberry juice or blueberry anthocyanins (0.2 mg/mL), body fat (%) was not different from those mice fed the LF diet. Anthocyanins (ACNs) decreased retroperitoneal and epididymal adipose tissue weights. Fasting serum glucose concentrations were higher in mice fed the HF45 diet. However, it was reduced to LF levels in mice fed the HF45 diet plus 0.2 mg of ACNs/mL in the drinking water, but not with blueberry juice. beta cell function (HOMA-BCF) score was lowered with HF45 feeding but returned to normal levels in mice fed the HF45 diet plus purified ACNs (0.2 mg/mL). Serum leptin was elevated in mice fed HF45 diet, and feeding either blueberry juice or purified ACNs (0.2 mg/mL) decreased serum leptin levels relative to HF45 control. Sucrose in drinking water, when consumption was restricted to the volume of juice consumed, produced lower serum leptin and insulin levels, leptin/fat, and retroperitoneal and total fat (% BW). Blueberry juice was not as effective as the low dose of anthocyanins in the drinking water in preventing obesity. Additional studies are needed to determine factors responsible for the differing responses of blueberry juice and whole blueberry in preventing the development of obesity.

Subcritical solvent extraction of anthocyanins from dried red grape pomace.

Accelerated solvent extraction (ASE) was used to optimize and determine the effectiveness of an alternative, environmentally friendly extraction procedure using subcritical solvents to recover anthocyanins from freeze-dried, ground Sunbelt red grape pomace. Anthocyanins were extracted from pomace using the following ASE variables: pressure (6.8 MPa), one extraction cycle, and temperature (40, 60, 80, 100, 120, and 140 degrees C). Conventional solvent extraction with methanol/water/formic acid (60:37:3 v/v/v) was compared to four hydroethanolic solvents (10, 30, 50, and 70% ethanol in water, v/v). Anthocyanins in the extracts were identified and quantified by HPLC-MS and HPLC. There was an insignificant interaction between solvent and temperature (p = 0.0663). Solvents containing 70 and 50% ethanol in water extracted more total anthocyanins (463 and 455 mg/100 g of DW, respectively) than other solvents. The total amounts of anthocyanins extracted at 100 degrees C (450 mg/100 g of DW), 80 degrees C (436 mg/100 g of DW), and 120 degrees C (411 mg/100 g of DW) were higher than at the other temperatures. Solvents containing 70 and 50% ethanol in water extracted similar amounts of anthocyanins as conventional extraction solvent.