Ronald L Prior

Ronald L Prior
University of Arkansas | U of A · Department of Food Science

About

325
Publications
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55,018
Citations
Citations since 2017
4 Research Items
17286 Citations
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201720182019202020212022202305001,0001,5002,0002,5003,000
201720182019202020212022202305001,0001,5002,0002,5003,000
201720182019202020212022202305001,0001,5002,0002,5003,000

Publications

Publications (325)
Article
Full-text available
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 temperatu...
Article
The berry consumption have been associated with cardiovascular disease prevention in recent years. Atherosclerosis is one of the major causes of cardiovascular diseases. However, research on the prevention of atherosclerosis through consuming individual whole berries, specifically direct evidence, remains scarce. Therefore, further elucidating the...
Article
American cranberry (Vaccinium macrocarpon) is native to Eastern North America. Recent studies have suggested that the A-type proanthocyanidins (PACs) in cranberries are effective in preventing urinary tract infection. To meet the growing interest in the cranberry market, an accurate, reliable, and simple method to determine PAC concentration is nee...
Article
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 b...
Article
Full-text available
BACKGROUND: Fruits and berries are known to contain relatively high amounts of antioxidant/bioactive compounds. Several methods have been used for measurement of antioxidant capacity (AC), but not all methods have direct relevance to in vivo antioxidant status. OBJECTIVE: Determine AC in berry/fruit samples, processed berry products, and purified c...
Article
Full-text available
BACKGROUND: Products derived from black chokeberry are claimed to be beneficial in treating chronic diseases, such as obesity and diabetes. OBJECTIVE: The objective of this study was to determine if supplementation with Aronia melanocarpa (black chokeberry) juice concentrate (AJC) has anti-obesity properties in mice fed obesogenic diets. METHODS: M...
Article
Full-text available
The concept of oxidative stress, the factors responsible for oxidative stress and on those substances in foods that may have in vivo effects in terms of decreasing the adverse effects of reactive oxygen species (ROS) and reactive nitrogen species (RNS) on normal physiological function are reviewed. Methods of analysis of dietary redox reactive comp...
Article
Full-text available
BACKGROUND: Strawberry puree color is unstable during processing and storage due to oxidative reactions. OBJECTIVE: To determine if strawberry puree prepared under nitrogen or carbon dioxide would result in greater retention of color and anthocyanins than samples prepared under air. METHODS: Purees prepared under carbon dioxide, nitrogen or air wer...
Article
Chokeberries are an excellent source of polyphenols, but their fate during juice processing and storage are unknown. The stability of anthocyanin's, total proanthocyanidins, hydroxycinnamic acids, and flavonols at various stages of juice processing and over six months of storage at 25 oC were determined. Flavonols, total proanthocyanidins and hydro...
Article
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 were studied, using HPLC/MS/MS, in rats fed AIN93G based diets containing 5% (dry weight basis) of either cranberry (CB)...
Article
An improved method for the measurement of oxygen radical absorbance capacity (ORAC) was developed and validated using fluorescein (3',6'-dihydroxyspiro[isobenzofuran-1[3H], 9'[9H]-xanthen]-3-one) as a new fluorescence probe (ORAC(FL)). Randomly methylated beta-cyclodextrin (RMCD) was introduced as the water-solubility enhancer for lipophilic antiox...
Article
Chokeberry anthocyanins are susceptible to degradation during processing and storage of processed products. In this study we determined the effects of three pH levels (2.8, 3.2, and 3.6) and four beta cyclodextrin (BCD) concentrations (0, 0.5, 1, and 3%) alone and in combination on the stability of chokeberry juice anthocyanins before and after pas...
Article
Full-text available
Despite the well-accepted notion that early maternal influences persist beyond fetal life and may underlie many adult diseases, the risks imposed by the maternal environment on breast cancer development and underlying biological mechanisms remain poorly understood. Here, we investigated whether early exposure to blueberry [BB] via maternal diet alt...
Article
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% f...
Article
Thousands of tons of crude caffeine are produced annually in the decaffeination of coffee. Crude caffeine is further purified to obtain pure caffeine, and the non-caffeine residue is typically discarded as waste. In the present study, we discovered that crude caffeine possessed unexpected bioactive properties. Crude caffeine had potent hydrophilic...
Chapter
Anthocyanins are water-soluble plant pigments responsible for the blue, purple, and red color of many plant tissues. Over 600 naturally occurring anthocyanins have been reported and they vary in: (1) the number and position of hydroxyl and methoxyl groups on the basic anthocyanidin skeleton; (2) the identity, number, and positions at which sugars a...
Article
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 pol...
Article
Full-text available
Mammary stem cells are undifferentiated epithelial cells, which initiate mammary tumors and render them resistant to anticancer therapies, when deregulated. Diets rich in fruits and vegetables are implicated in breast cancer risk reduction, yet underlying mechanisms are poorly understood. Here, we addressed whether dietary factors selectively targe...
Article
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+L...
Article
The supercritical CO2-decaffeination process causes unroasted coffee beans to turn brown. Therefore, we suspected that the decaffeinated beans contained melanoidins. Decaffeinated unroasted coffee extract absorbed light at 405 nm with a specific extinction coefficient, Kmix 405 nm, of 0.02. Membrane dialysis (molecular weight cut-off, 12 to 14 kDa)...
Article
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 conce...
Article
Full-text available
Anthocyanins are responsible for the color of many flowers, fruits, and vegetables. An interesting and unique Purple (Pr) gene mutation in cauliflower (Brassica oleracea var botrytis) confers an abnormal pattern of anthocyanin accumulation, giving the striking mutant phenotype of intense purple color in curds and a few other tissues. To unravel the...
Article
The effect of feeding cranberry pomace (CBP) on selected metabolic parameters associated with high fructose feeding (58% by weight) was investigated in growing Sprague–Dawley rats. Compared to a positive control (modified AIN93 diet), high fructose feeding increased fasting plasma insulin, cholesterol, and triacylglycerols (TAG), post-prandial plas...
Article
(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 berr...
Article
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 an...
Article
Full-text available
BACKGROUND: Blueberry anthocyanins are susceptible to degradation during juice processing and storage of juice at ambient temperature. Methods are needed to stabilize the health-promoting anthocyanins in blueberry and other anthocyanin-rich berry juices. OBJECTIVE: In this study we determined the effect of acidification (pH 2.1, 2.5 and 2.9) of blu...
Article
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 perf...
Article
The objective of this study was to validate an improved 4-dimethylaminocinnamaldehyde (DMAC) colorimetric method using a commercially available standard (procyanidin A2), for the standard method for quantification of proanthocyanidins (PACs) in cranberry powders, in order to establish dosage guidelines for the uropathogenic bacterial anti-adhesion...
Article
Fruit by-products are rich sources of procyanidins and anthocyanins known for potential health benefits. Freeze dried blueberry pomace and grape pomace were heated in a forced air oven at 40, 60, 105, and 125 °C for 72, 48, 16, and 8 h respectively, to study the stability of procyanidins and total anthocyanins. Heating decreased procyanidin concent...
Article
Dietary flavonoids can be converted into phenolic acids by colonic microflora. Phenolic acids can then be absorbed into the circulation and may contribute to the health-promoting effects of the parent compounds. Phenolic acids can be further metabolized in other tissues via methylation and conjugation with glucuronide or sulfate. The objectives of...
Article
Anthocyanins (ACNs) from various foods have been shown to minimize the development of obesity in some animal models. The objective of the current study was to compare the effects of feeding purified black raspberry (BRB) ACNs or the freeze-dried whole BRB on the development of obesity. Male C57BL/6J mice (25 days of age) were assigned at random to...
Article
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 treatmen...
Article
The effect of dietary consumption of a cranberry powder (CP) containing increased amounts of procyanidins and other phytochemicals on metabolic parameters associated with metabolic syndrome was investigated in growing rats fed a high fructose diet. Dietary treatments were control (starch based), high fructose (HF), and HF containing either 3.3, 6.6...
Article
The proximate composition and identification and quantification of polyphenolic compounds in dried cranberry pomace were determined. Proximate analysis was conducted based on AOAC methods for moisture, protein, fat, dietary fiber, and ash. Other carbohydrates were determined by the difference method. Polyphenolic compounds were identified and quant...
Article
Cranberry pomace was mixed with corn starch in various ratios (30:70, 40:60, 50:50 pomace/corn starch DW) and extruded using a twin-screw extruder at three temperatures (150, 170, 190 degrees C) and two screw speeds (150, 200 rpm). Changes in the anthocyanin, flavonol, and procyanidin contents due to extrusion were determined by HPLC. Antioxidant c...
Article
Full-text available
We hypothesized that consumption of soy protein isolate (SPI) or the soy isoflavone genistein (GEN) would modulate mRNA expression of genes underlying lipid and thyroid hormone metabolism in livers and small intestines of young adult male Sprague-Dawley rats. Early pregnant rat dams were placed on AIN-93G diets containing casein (CAS, control prote...
Article
Male C57BL/6 mice received diets with either 10% of kcal from fat, or a high fat diet [45% (HF45) or 60% (HF60) kcal from fat]. Diets were prepared with or without freeze-dried powders (10%) from whole blueberries (BB), strawberries (SB), Concord grape or black raspberry. In the 2nd study, purified anthocyanins (ACNs) from SB or BB were added to th...
Article
Early developmental events influence the fine tuning of later susceptibility to adult diseases. Diet is a determinant of breast cancer risk, and our previous studies showed that diet-mediated changes in transcriptional programs promote early mammary gland differentiation. Although consumption of fruits is considered to elicit multiple health benefi...
Article
Fruits and fruit byproducts are rich sources of polyphenols, including procyanidins, which are known to have numerous potential health benefits. This study investigated if varietal differences existed in the procyanidin composition of grape seed and if soaking in extraction solvent overnight prior to extraction improved the recovery of procyanidins...
Article
Full-text available
Background Blueberries may lower relative risk for cancers of the gastrointestinal tract. Previous work indicated an inhibitory effect of consumed blueberry (BB) on formation of aberrant crypt foci (ACF) in colons of male Fisher F344 rats (inbred strain). However, effects of BB on colon tumors and in both genders are unknown. Methods We examined e...
Article
Unlabelled: Grape juice processing by-products, grape seed and pomace are a rich source of procyanidins, compounds that may afford protection against chronic disease. This study was undertaken to identify optimal extrusion conditions to enhance the contents of monomers and dimers at the expense of large molecular weight procyanidin oligomers and p...
Article
Evaluation of different tissues of Artemisia annua for their nutritional contents and antioxidant potential demonstrated that the leaves and inflorescences had the highest percentage of protein, crude fat and in vitro digestible fractions but the lowest levels of detergent fibres. These tissues also had the highest composition of the major elements...
Article
Full-text available
Since metabolism of energy is a major source of reactive oxygen species, the quantity of dietary antioxidants needed may be related to energy consumption. Antioxidant status in vivo can be altered by diet, but the postprandial response is dependent upon factors such as 1) antioxidant capacity (AOC) of food, 2) amount consumed, 3) type of phytochemi...
Article
Full-text available
The quantitative parameters and method performance for a normal-phase HPLC separation of flavanols and procyanidins in chocolate and cocoa-containing food products were optimized and assessed. Single laboratory method performance was examined over three months using three separate secondary standards. RSD(r) ranged from 1.9%, 4.5% to 9.0% for cocoa...
Article
Black raspberries (BRB) contain high levels of polyphenols and have been demonstrated to be chemopreventive. In order to investigate the underlying mechanism and study the metabolism of anthocyanins, pigs were fed freeze-dried BRB powder or purified diet (control) and three segments of the gastrointestinal (GI) tract (small intestine, cecum, and co...
Article
Full-text available
Blueberry juice processing by-products are a rich source of procyanidins, which comprise a group of compounds shown to possess numerous health benefits, including protection against coronary heart disease, type II diabetes, and obesity. Most of the procyanidins present in blueberry pomace, however, are large molecular weight compounds that are poor...
Article
Blueberries are a rich source of procyanidins that may contribute to the reduced risk of chronic disease; however, because of seasonal availability, the berries are commonly consumed in thermally processed forms after long-term storage. In this study, we evaluated the effects of processing and 6 months of storage on procyanidin composition and cont...
Article
Glucuronide conjugates of soy isoflavone metabolites genistein, daidzein, glycitein and equol in urinary samples from women, female pigs and female rats were pretreated with methanol instead of solid phase extraction or liquid-liquid extraction after enzymatic digestion. The samples were analyzed using an LC-ESI-MS/MS ion trap system. Analysis of r...
Article
Flavonoids and/or phenolic acids are the major components responsible for antioxidant capacity in fruits and vegetables. Recent research has shown that flavonoids are absorbed in humans, although the bioavailablity of these dietary components is not completely clear. Some epidemiological evidence demonstrates a reduced risk of cardio- and cerebrova...
Article
This study evaluated the effects of processing and 6 mo of storage on total monomeric anthocyanins, percent polymeric color, and antioxidant capacity of black raspberries that were individually quick-frozen (IQF), canned-in-syrup, canned-in-water, pureed, and juiced (clarified and nonclarified). Total monomeric anthocyanins, percent polymeric color...
Article
Full-text available
This study evaluated the effects of processing and 6 mo of storage on total monomeric anthocyanins, percent polymeric color, and antioxidant capacity of blueberries that were canned in syrup (CS), canned in water (CW), pureed, and juiced (clarified and nonclarified). Total monomeric anthocyanins, percent polymeric color, and oxygen radical absorbin...
Article
Total antioxidant capacity (TAC) provides an assessment of antioxidant activity and synergistic interactions of redox molecules in foods and plasma. We investigated the validity and reproducibility of food-frequency questionnaire (FFQ)-based TAC estimates assessed by oxygen radical absorbance capacity (ORAC), total radical-trapping antioxidant para...
Article
BACKGROUND: Flavonoids in different spinach genotypes were separated, identified, and quantified by a high-performance liquid chromatographic method with photodiode array and mass spectrometric detection. The antioxidant capacities of the genotypes were also measured using two antioxidant assays–oxygen radical absorbance capacity (ORACFL) and photo...
Article
Male C57BL/6J mice received diets with either 10% of calories from fat (LF) or a high-fat diet [45% (HF45) or 60% (HF60) calories from fat] for 92 days (expt 1) or 70 days (expt 2). These were given with or without freeze-dried powders from whole blueberries (BB) or strawberries (SB) (expt 1) or purified anthocyanin extracts from BB or SB (expt 2)....
Article
Blackberries are a rich source of polyphenolics, particularly anthocyanins, that may contribute to the reduced risk of chronic disease; however, as with most berries, the fresh fruit are only seasonally available. With most of the blackberries consumed as frozen or in thermally processed forms after long-term storage, the purpose of this study was...
Article
Blackberries ( Rubus sp.) were evaluated by high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS) to identify the ellagitannins present in flesh, torus (receptacle tissue), and seeds. Most ellagitannins were prese...
Article
Catechins and procyanidins are beneficial for human health; however, their bioavailability is low. The effect of food processing on catechin bioavailability from sources containing predominantly procyanidins has not been studied. The sumac sorghum mixture (50% whole grain+50% bran) used in this study contained catechins, procyanidins dimers, and po...
Article
Sorghum bran is concentrated with procyanidins (predominately polymers), which may be beneficial for health in humans; however, the bioavailability of procyanidins is not well-understood. Female Sprague-Dawley rats were fed an AIN93G diet containing 0, 5, 10, 20, or 40% Hi-tannin sorghum bran (n = 5-7 for each group) for 50 days. Sorghum bran conta...
Article
Full-text available
Determine 1) if consumption of a meal of different fruits or berries increases plasma hydrophilic (H-) or lipophilic (L-) antioxidant capacity (AOC) measured as Oxygen Radical Absorbance Capacity (ORAC(FL)); 2) if including macronutrients in the meal alters postprandial changes in AOC; and 3) if preliminary recommendations can be developed for anti...
Chapter
The measurement of both lipophilic and hydrophilic antioxidant capacity in food is possible using the oxygen radical absorbance capacity (ORAC FL) assay. Data from these measurements provide a measure of antioxidant capacity using specific biologically relevant free radical sources, usually the peroxyl radical, but different radical sources can be...