Sensory descriptive analysis of hard ciders from the Northeast and Mid-Atlantic United States.

Although alcoholic or "hard" cider is a beverage of growing popularity throughout the Northeastern and Mid-Atlantic United States (US), the industry lacks a consistent language for describing the sensory quality of its products. The main objective of this research was to explore the sensory attributes that can be used to describe a large representative sample (N = 42 samples) of ciders from Virginia, Vermont, and New York, using classical descriptive analysis (DA). The secondary objective of the research was to determine if cider samples' sensory attributes differ based on extrinsic factors, such as style, packaging, and apple varieties. The study was conducted using a standard DA: 8 panelists were trained for 13 h to develop a lexicon of aroma, taste, and mouthfeel descriptors for 42 cider samples (15 single varietal ciders, 27 blended ciders). Then, subjects evaluated each cider in duplicate for all descriptive attributes in standard sensory-evaluation conditions. Results were analyzed to determine overall differences among the individual cider samples, geographic origins, cider styles, and packaging formats, as well as significant differences across individual attributes. Herein, we report on 29 attributes that can be used to discriminate cider samples, as well as a subset of attributes which differentiate ciders based on extrinsic product variables. These results provide a framework for describing ciders from the Northeast and Mid-Atlantic regions of the US, which may be further generalizable to other North American ciders. As well, these results highlight the potential for more descriptive, sensory-based style guidelines may inspire future research related to cider production practices and terroir.

Grape pomace and its secondary waste management: Biochar production for a broad range of lead (Pb) removal from water.

Grape pomace (GP) management has been a challenge worldwide. We have previously demonstrated a biorefinery process to recover oil and polyphenols, and produce biofuels from GP sequentially, although over 50% of GP solid waste remains post-processing. To approach zero solid waste during GP processing, herein a pyrolysis process was designed for converting GP and its secondary processing wastes to biochars, which were then evaluated for lead (Pb) adsorption from water. GP lignin pyrolyzed at 700 °C (GPL2700 biochar) with specific surface area of 485 m2/g showed the highest Pb adsorption capacity, and achieved 66.5% of Pb removal from an initially high concentration of 300 mg/L within 30 min. At low initial Pb concentrations (50-3000 µg/L), GPL2700 biochar could reduce Pb concentrations to 0.208-77.2 µg/L. In addition, experimental and modeling results revealed that both physisorption and chemisorption mechanisms were involved in the adsorption process of GPL2700 biochar.

Compositional variability of food wastes and its effects on acetone-butanol-ethanol fermentation.

Converting food waste into butanol via acetone, butanol, and ethanol (ABE) fermentation provides the potential to recover energy and value-added chemicals from food waste. However, the high variability of food waste compositions has hindered the consistency and predictability of butanol production, impeding the development of a robust industrial fermentation process. This study characterized the compositional variation of collected food wastes and determined correlations between food waste compositional attributes and butanol yields for a better prediction of food waste fermentation with Clostridium. The total sugar, starch, fiber, crude protein, fat and ash contents (on dry basis) in the food waste samples were in a range of 0.5-53.5%, 0-25.2%, 0.6-26.9%, 5.5-21.5%, 0.1-37.9%, and 1.4-13.7%, respectively. The high variability of food waste composition resulted in a wide range (3.5-11.5 g/L) of butanol concentrations with an average of 8.2 g/L. Pearson's correlation analysis revealed that the butanol concentrations were strongly and positively correlated with equivalent glucose and starch contents in food waste, strongly and negatively correlated with fiber content, and weakly correlated with total sugar, protein, fat, and ash contents. The regression models constructed based on equivalent glucose and fiber contents reasonably predicted the butanol concentration, with the R2 of 0.80. Our study investigated the variability of food waste composition and, for the first time, unveiled relationships between food waste compositional attributes and fermentation yields, contributing to a greater understanding of food waste fermentation, which, in turn, assists in developing new strategies for increased consistency and predictability of food waste fermentation.

Preference for and sensitivity to flavanol mean degree of polymerization in model wines is correlated with body composition.

Bitterness and astringency (dryness) are characteristic sensory attributes of flavanol-rich foods. The degree of polymerization (DP) of flavanols influences their bitter and astringent sensations. Smaller DP compounds can enter the papillae on the tongue, eliciting a bitter response. Larger DP compounds are sterically inhibited from entering papillae and instead interact with oral proteins, cause precipitation, and elicit astringent sensations. Previous research has indicated that bitterness preference is related to health status, density of fungiform papillae on the tongue, and sensitivity to bitter compounds such as 6-n-propyl-thiouracil (PROP). The purpose of this study was to examine trends in liking, bitterness intensity, and astringency intensity of wine-like products with flavanols of different DP using a consumer sensory panel. Participants (n = 102) were segmented by phenotypes: body fat percentage (BF%), body mass index (BMI), PROP sensitivity, and stated bitter food preference. Differences in wine liking, perceived bitterness intensity, and astringency intensity were observed between three model wine samples of varying flavanol mean degrees of polymerization (mDP, i.e. the average size (polymer length) of flavanol compounds in a mixture). Specifically, with increased mDP, overall liking and bitterness liking decreased, with concurrent increased perception of bitterness and astringency intensity. Greater differences between phenotypes were observed when participants were segmented by BF% and BMI classification, than when segmented by PROP sensitivity classification. Reduced ability to detect differences in bitterness and astringency were noted in participants of higher weight status. Overall, these data suggest that weight status in adults is a greater predictor of liking of flavanol-rich foods than bitterness sensitivity (as determined by PROP classification), and that reduced perception of bitterness and astringency associated with weight gain may impact selection and preference for these foods.

Flavanol Polymerization Is a Superior Predictor of α-Glucosidase Inhibitory Activity Compared to Flavanol or Total Polyphenol Concentrations in Cocoas Prepared by Variations in Controlled Fermentation and Roasting of the Same Raw Cocoa Beans.

Raw cocoa beans were processed to produce cocoa powders with different combinations of fermentation (unfermented, cool, or hot) and roasting (not roasted, cool, or hot). Cocoa powder extracts were characterized and assessed for α-glucosidase inhibitory activity in vitro. Cocoa processing (fermentation/roasting) contributed to significant losses of native flavanols. All of the treatments dose-dependently inhibited α-glucosidase activity, with cool fermented/cool roasted powder exhibiting the greatest potency (IC50: 68.09 µg/mL), when compared to acarbose (IC50: 133.22 µg/mL). A strong negative correlation was observed between flavanol mDP and IC50, suggesting flavanol polymerization as a marker of enhanced α-glucosidase inhibition in cocoa. Our data demonstrate that cocoa powders are potent inhibitors of α-glucosidase. Significant reductions in the total polyphenol and flavanol concentrations induced by processing do not necessarily dictate a reduced capacity for α-glucosidase inhibition, but rather these steps can enhance cocoa bioactivity. Non-traditional compositional markers may be better predictors of enzyme inhibitory activity than cocoa native flavanols.

Compositional Characterization of Different Industrial White and Red Grape Pomaces in Virginia and the Potential Valorization of the Major Components.

To better evaluate potential uses for grape pomace (GP) waste, a comprehensive chemical composition analysis of GP in Virginia was conducted. Eight commercial white and red pomace samples (cv. Viognier, Vidal Blanc, Niagara, Petit Manseng, Petit Verdot, Merlot, Cabernet Franc, and Chambourcin) obtained from different wineries in Virginia, USA were used. For extractives, GPs contained 2.89%-4.66% titratable acids, 4.32%-6.60% ash, 4.62%-12.5% lipids with linoleic acid being the predominant (59.0%-70.9%) fatty acid, 10.4-64.8 g total phenolic content (gallic acid equivalents)/kg GP, 2.09-53.3 g glucose/kg GP, 3.79-52.9 g fructose/kg GP, and trace sucrose. As for non-extractives, GPs contained 25.2%-44.5% lignin, 8.04%-12.7% glucan, 4.42%-7.05% xylan, and trace amounts of galactan, arabinan, and mannan (less than 3% in total). Potential usages of these components were further examined to provide information on better valorization of GP. Considering the valuable extractives (e.g., polyphenols and oil) and non-extractives (e.g., lignin), designing a biorefinery process aiming at fully recover and/or utilize these components is of future significance.

Comparison of Common Analytical Methods for the Quantification of Total Polyphenols and Flavanols in Fruit Juices and Ciders.

Multiple analytical methods are used for quantification of total polyphenols and total flavanols in fruit juices and beverages. Four methods were evaluated in this study: Folin-Ciocalteu (F-C), Lowenthal permanganate (L-P), 4-dimethylaminocinnamaldehyde (DMAC), and the bovine serum albumin (BSA) precipitation method. Method validation parameters, including working range, limit of detection, limit of quantitation, precision (repeatability), accuracy, and specificity, were assessed and compared. The F-C method was not specific to polyphenols, and the L-P method had the widest working range but lacked accuracy. The DMAC method was the most specific to flavanols, and the BSA method was not suitable for quantification of smaller flavanols, such as catechin and epicatechin. Quantitative performance was evaluated using commercial fruit juice samples (n = 14), apple juice samples of different cultivars (n = 22), and commercial ciders (n = 17). In general, the L-P titration method and DMAC method resulted in higher quantitative values than the F-C method and BSA precipitation method, respectively. However, ratios of results obtained by the L-P and F-C method ranged from 1 to 28, and ratios of results obtained by the DMAC and BSA precipitation method ranged from <1 to 280. This tremendous variation is likely due to variation in polyphenol composition and sample matrix. This information provides perspective for comparison of results obtained through these different methods, and a basis for choosing the most appropriate analytical method for quantification of polyphenols to address a specific research question when working with commercial fruit juice, apple juice from different apple cultivars, and commercial ciders. PRACTICAL APPLICATION: This study compared results obtained when four common polyphenol quantification methods were applied to a diverse selection of fruit juices and beverages with distinct polyphenol composition and sample matrix. The matrix and polyphenol composition of the samples significantly influenced the results. Our findings can help manufacturers of fruit-based products choose the most appropriate analytical method for polyphenol quantification as part of a quality assurance program or to convey information on dietary polyphenol content to consumers. An assessment of analytical method validation parameters is provided for each of the four methods, which will help users of these methods to understand their limitations.

Flavanol supplementation protects against obesity-associated increases in systemic interleukin-6 levels without inhibiting body mass gain in mice fed a high-fat diet.

Weight gain and obesity are associated with increased levels of proinflammatory cytokines. Studies have demonstrated the ability of dietary flavanols to reduce the severity of metabolic derangements due to high-fat (HF) feeding. The degree of polymerization of the flavanols appears to play a role in determining the extent of these protective effects. This study evaluated the preventative effects of grape seed and pine bark flavanol supplementation, with significantly different flavanol degree of polymerization, in the context of an HF diet. For 13 weeks, mice were given 35 mg/kg body weight per day grape seed or pine bark as part of an HF diet and compared to mice fed a low-fat diet and control HF diet. All flavanol-supplemented groups and the HF control incurred significantly higher weight gain compared to the lean control, and the grape seed group gained significantly more weight than the HF control. Increased weight gain of treatment groups was likely caused by hyperphagia. Despite lack of improvements to weight gain and glycemic control, it was observed that all flavanol treatment groups were able to significantly reduce interleukin-6 compared to HF control. The grape seed group, which gained the most weight overall, also exhibited the lowest levels of interleukin-6 compared to other groups. Overall, low-dose flavanol extract supplementation, regardless of mean degrees of polymerization, blunted cytokine production despite increased weight gain. This obesity-independent effect suggests flavanols may be used as complementary interventions to ameliorate increased inflammatory tone in the contexts of obesity and diabetes. Furthermore, flavanol-induced hyperphagia may have use for attenuation of cachexia.

Development and Characterization of a Pilot-Scale Model Cocoa Fermentation System Suitable for Studying the Impact of Fermentation on Putative Bioactive Compounds and Bioactivity of Cocoa.

Cocoa is a concentrated source of dietary flavanols-putative bioactive compounds associated with health benefits. It is known that fermentation and roasting reduce levels of native flavonoids in cocoa, and it is generally thought that this loss translates to reduced bioactivity. However, the mechanisms of these losses are poorly understood, and little data exist to support this paradigm that flavonoid loss results in reduced health benefits. To further facilitate large-scale studies of the impact of fermentation on cocoa flavanols, a controlled laboratory fermentation model system was increased in scale to a large (pilot) scale system. Raw cocoa beans (15 kg) were fermented in 16 L of a simulated pulp media in duplicate for 168 h. The temperature of the fermentation was increased from 25⁻55 °C at a rate of 5 °C/24 h. As expected, total polyphenols and flavanol levels decreased as fermentation progressed (a loss of 18.3% total polyphenols and 14.4% loss of total flavanols during fermentation) but some increases were observed in the final timepoints (120⁻168 h). Fermentation substrates, metabolites and putative cocoa bioactive compounds were monitored and found to follow typical trends for on-farm cocoa heap fermentations. For example, sucrose levels in pulp declined from >40 mg/mL to undetectable at 96 h. This model system provides a controlled environment for further investigation into the potential for optimizing fermentation parameters to enhance the flavanol composition and the potential health benefits of the resultant cocoa beans.

Development of a rapid ultra performance hydrophilic interaction liquid chromatography tandem mass spectrometry method for procyanidins with enhanced ionization efficiency.

Cocoa flavanols (catechins and procyanidins) can exist in various polymerization states and are commonly classified by their degree of polymerization (DP). There is increasing evidence that flavanols of distinct DP possess different biological activities, but separation and quantification of the higher DP procyanidins is challenging and has thus created the need for new methodologies that utilize advancements in columns and LC-MS/MS systems. An aqueous normal phase (hydrophilic interaction liquid chromatography, HILIC), UPLC method with post-column ESI adjuvant infusion was developed to reduce the total analysis time, increase peak separation, and increase detection specificity (compared to traditional fluorescence methods) by coupling with mass spectrometry detection. The total elution time was reduced from 70 to 90 min (typically used for normal phase and HILIC HPLC separation of procyanidins) down to 9 min by employing UPLC. Results indicate that by using a post-column 0.04 M ammonium formate infusion (5 µL/min), ionization of procyanidins was significantly enhanced. Lower limits of detection ranged from 3.19 × 10-2 to 4.56 pmol-on-column, and lower limits of quantification ranged from 2.79 × 10-2 to 1.17 × 102 pmol-on-column across compounds DP 1-9. This method builds upon the foundation set by existing analytical methods and employs new technologies to dramatically increase sample throughput and enhance detection limits and specificity, facilitating improved analysis for procyanidins.

Free amino nitrogen concentration correlates to total yeast assimilable nitrogen concentration in apple juice.

Yeast assimilable nitrogen (YAN) is essential for yeast growth and metabolism during apple (Malus x domestica Borkh.) cider fermentation. YAN concentration and composition can impact cider fermentation kinetics and the formation of volatile aroma compounds by yeast. The YAN concentration and composition of apples grown in Virginia, USA over the course of two seasons was determined through analysis of both free amino nitrogen (FAN) and ammonium ion concentration. FAN was the largest fraction of YAN, with a mean value of 51 mg N L-1 FAN compared to 9 mg N L-1 ammonium. Observed YAN values ranged from nine to 249 mg N L-1, with a mean value of 59 mg N L-1. Ninety-four percent of all samples analyzed in this study contained <140 mg N L-1 YAN, a concentration generally considered the minimum level needed in grape-based wines for yeast to fully utilize all of the fermentable sugars. FAN concentration was correlated with total YAN concentration, but ammonium concentration was not. Likewise, there was no correlation between FAN and ammonium concentration.

Flavanol concentrations do not predict dipeptidyl peptidase-IV inhibitory activities of four cocoas with different processing histories.

Cocoa and its constituent bioactives (particularly flavanols) have reported anti-diabetic and anti-obesity activities. One potential mechanism of action is inhibition of dipeptidyl peptidase-IV (DPP4), the enzyme that inactivates incretin hormones such as glucagon-like peptide-1 and gastric inhibitory peptide. The objective of this study was to determine the DPP4 inhibitory activities of cocoas with different processing histories, and identify processing factors and bioactive compounds that predict DPP4 inhibition. IC25 values (µg mL-1) were 4.82 for Diprotin A (positive control), 2135 for fermented bean extract, 1585 for unfermented bean extract, 2871 for unfermented liquor extract, and 1076 for fermented liquor extract This suggests mild inhibitory activity. Surprisingly, protein binding activity, total polyphenol, total flavanol, individual flavanol and complex fermentation/roasting product levels were all positively correlated to IC25 concentrations (greater levels correspond to less potent inhibition). For the representative samples studied, fermentation appeared to improve inhibition. This study suggests that cocoa may possess mild DPP4 inhibitory activity, and that processing steps such as fermentation may actually enhance activity. Furthermore, this activity and the variation between samples were not easily explainable by traditional putative bioactives in cocoa. The compounds driving this activity, and the associated mechanism(s) by which this inhibition occurs, remain to be elucidated.

The interactive effect of fungicide residues and yeast assimilable nitrogen on fermentation kinetics and hydrogen sulfide production during cider fermentation.

BACKGROUND: Fungicide residues on fruit may adversely affect yeast during cider fermentation, leading to sluggish or stuck fermentation or the production of hydrogen sulfide (H2 S), which is an undesirable aroma compound. This phenomenon has been studied in grape fermentation but not in apple fermentation. Low nitrogen availability, which is characteristic of apples, may further exacerbate the effects of fungicides on yeast during fermentation. The present study explored the effects of three fungicides: elemental sulfur (S0 ) (known to result in increased H2 S in wine); fenbuconazole (used in orchards but not vineyards); and fludioxonil (used in post-harvest storage of apples). RESULTS: Only S0 led to increased H2 S production. Fenbuconazole (≥0.2 mg L-1 ) resulted in a decreased fermentation rate and increased residual sugar. An interactive effect of yeast assimilable nitrogen (YAN) concentration and fenbuconazole was observed such that increasing the YAN concentration alleviated the negative effects of fenbuconazole on fermentation kinetics. CONCLUSION: Cidermakers should be aware that residual fenbuconazole (as low as 0.2 mg L-1 ) in apple juice may lead to stuck fermentation, especially when the YAN concentration is below 250 mg L-1 . These results indicate that fermentation problems attributed to low YAN may be caused or exacerbated by additional factors such as fungicide residues, which have a greater impact on fermentation performance under low YAN conditions. © 2016 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Characterization of the polyphenol composition of 20 cultivars of cider, processing, and dessert apples (Malus × domestica Borkh.) grown in Virginia.

Polyphenols and maturity parameters were determined in 20 apple cultivars with potential for hard cider production grown in Virginia, U.S.A. Concentrations of five classes of polyphenols were significantly different across cultivar for both peel and flesh. Total polyphenol concentration ranged from 0.9 µg/g wwb in flesh of Newtown Pippin to 453 µg/g wwb in peel of Red Delicious. Harrison, Granny Smith, Rome, Winesap, and Black Twig cultivars contained the highest concentration of total flavan-3-ols in flesh, indicating potential to impart desired astringency and bitterness to cider under processing conditions where extraction of polyphenols from peel is minimal. These results can inform selection of fruit juice, extracts, and byproducts for investigations of bioactivity and bioavailability of polyphenols, and provide baseline data for horticultural and processing research supporting the growing hard cider industry in Virginia. Based on these data, cultivars Harrison, Granny Smith, Rome, Winesap, and Black Twig show high potential for cider production in Virginia.

A cyclobutanone analogue mimics penicillin in binding to isopenicillin N synthase.

A carbocyclic analogue of the beta-lactam antibiotic isopenicillin N (IPN) has been synthesised and cocrystallised with isopenicillin N synthase (IPNS), the central enzyme in the biosynthesis of penicillin antibiotics. The crystal structure of the IPNS-cyclobutanone complex reveals an active site environment similar to that seen in the enzyme-product complex generated by turnover of the natural substrate within the crystalline protein. The IPNS-cyclobutanone structure demonstrates that the product analogue is tethered to the protein by hydrogen bonding and salt bridge interactions with its carboxylate groups, as seen previously for the natural substrate and product. Furthermore, the successful cocrystallisation of this analogue with IPNS provides firm structural evidence for the utility of such cyclobutanone derivatives as hydrolytically stable analogues of bicyclic beta-lactams.