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Cider Vinegar Production
Abstract
Cider vinegar or apple cider vinegar is the vinegar produced by the acetous fermentation
of apple cider, according to the Codex Alimentarius. In
other words, the primal raw material is apple juice or concentrated apple juice that
undergoes alcoholic fermentation, and after that, the produced cider is subjected to a
fermentation with acetic acid bacteria, for the final production of the vinegar. Cider vinegar is consumed and produced in several countries
around the world, mainly in the United States of America, the United Kingdom, and
Switzerland.
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The reduction of chemical fungicides in agriculture has led to the use of microorganisms as biocontrol agents. Starmerella bacillaris is a non-Saccharomyces yeast associated with overripe and botrytized grape berries microbiota. Its use has been proposed for wine fermentation because of yeast fructophilic character and high glycerol production. Recently, S. bacillaris has been demonstrated to possess antifungal activity against Botrytis cinerea on the grape. Penicillium expansum is the pathogen responsible for the blue mold rot, the most important postharvest disease of apples. These fruits are the raw material of the cider, an alcoholic beverage commonly produced using S. cerevisiae starter cultures. In this study 14 S. bacillaris strains have been studied to evaluate their postharvest antifungal activity against P. expansum on apples. Moreover, the fermentation performances in apple juice of these non-Saccharomyces strains were tested, both in single-strain fermentation and in sequential fermentation, together with S. cerevisiae. Four S. bacillaris strains, able to significantly decrease blue mold rot symptoms and to increase glycerol content during fermentation have been selected to improve apple and cider quality.
Wax apple fruit (Syzygium aqueum Alston cv. Taaptimjan) is a tropical fruit with many nutritional bioactive compounds and high economic value. However, when fully ripe, the thin-skinned fruit is highly susceptible to physical damage and microbial spoilage that significantly reduce its commercial value. The present study was aimed to find a suitable ripening stage between the ripe and overripe wax apple fruits for developing a value-added beverage specifically cider. The chemical profiles of ripe and overripe wax apple juice and cider were determined by measuring sugar, acid, alcohol, mineral, proximate, ascorbic acid, amino acid, antioxidant, and volatile levels. Overall, the results showed significant variations. The physicochemical and proximate analysis showed highest values for ripe fruit juice than overripe fruit juice and the cider samples. The amino acids in the samples were found almost at similar levels. Polyphenolic content and antioxidant activities were higher in ciders than in unfermented juices. In addition, the overripe fruit cider had more volatile compounds than ripe fruit cider and unfermented juices. Overall, the overripe fruit is suitable for producing cider, whereas the ripe fruit is more suitable for the unfermented beverages.
A randomized, clinical trial was performed to examine whether Apple cider vinegar (ACV) can result in dietary modifications that provides beneficial effects on the management of body weight and serum metabolic profiles in overweight or obese individuals. The participants (n = 39) were randomly allocated into the ACV (subjected to a restricted calorie diet (RCD) with 250 kcal/day energy deficit and 30 mL/d of ACV)) or the control group (RCD only) for 12 weeks. The ACV significantly reduced body weight, BMI, Hip circumference, visceral adiposity index (VAI) and appetite score (P ≤ 0.00). Furthermore, Plasma triglyceride (TG) and total cholesterol (TC) levels significantly decreased and high density lipoprotein cholesterol (HDL-C) concentration significantly increased in the ACV group in comparison to the control group (P ≤ 0.05). Thus, ACV along with RCD can be considered as an effective strategy for reducing anthropometric parameters, TG and TC level, VAI, appetite and increasing HDL-C concentration in overweight or obese individuals.
The global escalation in antibiotic resistance cases means alternative antimicrobials are essential. The aim of this study was to investigate the antimicrobial capacity of apple cider vinegar (ACV) against E. coli, S. aureus and C. albicans. The minimum dilution of ACV required for growth inhibition varied for each microbial species. For C. albicans, a 1/2 ACV had the strongest effect, S. aureus, a 1/25 dilution ACV was required, whereas for E-coli cultures, a 1/50 ACV dilution was required (p < 0.05). Monocyte co-culture with microbes alongside ACV resulted in dose dependent downregulation of inflammatory cytokines (TNFα, IL-6). Results are expressed as percentage decreases in cytokine secretion comparing ACV treated with non-ACV treated monocytes cultured with E-coli (TNFα, 99.2%; IL-6, 98%), S. aureus (TNFα, 90%; IL-6, 83%) and C. albicans (TNFα, 83.3%; IL-6, 90.1%) respectively. Proteomic analyses of microbes demonstrated that ACV impaired cell integrity, organelles and protein expression. ACV treatment resulted in an absence in expression of DNA starvation protein, citrate synthase, isocitrate and malate dehydrogenases in E-coli; chaperone protein DNak and ftsz in S. aureus and pyruvate kinase, 6-phosphogluconate dehydrogenase, fructose bisphosphate were among the enzymes absent in C.albican cultures. The results demonstrate ACV has multiple antimicrobial potential with clinical therapeutic implications.
Production of pectinases by Aspergillus niger was successfully carried out through solid state fermentation. Orange pomace was used as substrate to produce pectinases using a wild type of A. niger isolated from a rotten orange texture. Some of the important parameters affecting exo- and endo-pectinases activities such as temperature, moisture, C/N ratio were optimized. The results indicated that the produced pectinases exhibited maximum activity in temperature range of 45–55 °C and the maximum enzyme productivity occurred at 70% moisture content and C/N ratio of 10. The enzyme kinetic was studied using Michaelis–Menten and Logistic model and the equation were fitted to experimental data for both exo- and endo-pectinases activities. In evaluation of kinetic model, it was found that Monod model presented perfectly fitted with experimental data. Monod kinetic parameters \( (\mu_{max} \;{\text{and}}\;K_{S} ) \) for exo-pectinase activities were \( 771.7\,\upmu{\text{M}}\,{ \hbox{min} }^{ - 1} \;{\text{and}}\;31.91 \) mM, respectively. The Monod kinetic parameters \( ( \mu_{max} \;{\text{and}}\;K_{S} ) \) for endo-pectinase activity were \( 48.19\,{\text{mP}}\;{ \hbox{min} }^{ - 1} \) and \( 478.3\,{\text{mM}}, \) respectively. Finally, the performances of the produced pectinases were evaluated on natural apple juice. It was confirmed that concentration of soluble sugar, clarity and viscosity of the juice and the yield of extracted juice were significantly improved by the enzymatic hydrolysis activity of pectinases.
Yeast cryotolerance may be advantageous for cider making, where low temperatures are usually employed. Here, we crossed the cryotolerant S. eubayanus with a S. cerevisiae wine strain and assessed the suitability of the hybrids for low-temperature cider fermentation. All strains fermented the juice to 5% ABV, but at different rates; hybrid strains outperformed S. cerevisiae, which was sensitive to low temperatures. The best hybrid fermented similarly to S. eubayanus. S. eubayanus produced sulphurous off flavours which masked a high concentration of fruity ester notes. This phenotype was absent in the hybrid strains, resulting in distinctly fruitier ciders. Aroma was assessed by an independent consumer panel, which rated the hybrid ciders as identical to the wine strain cider. Both were significantly more pleasant than the S. eubayanus cider. Interspecific hybridization can apparently be used effectively to improve low-temperature fermentation performance without compromising product quality.
Electronic supplementary material
The online version of this article (doi:10.1007/s10295-017-1947-7) contains supplementary material, which is available to authorized users.
Organic apple cider vinegar is produced from apples that go through very restricted treatment in orchard. During the first stage of the process, the sugars from apples are fermented by yeasts to cider. The produced ethanol is used as a substrate by acetic acid bacteria in a second separated bioprocess. In both, the organic and conventional apple cider vinegars the ethanol oxidation to acetic acid is initiated by native microbiota that survived alcohol fermentation. We compared the cultivable acetic acid bacterial microbiota in the production of organic and conventional apple cider vinegars from a smoothly running oxidation cycle of a submerged industrial process. In this way we isolated and characterized 96 bacteria from organic and 72 bacteria from conventional apple cider vinegar. Using the restriction analysis of the PCR-amplified 16S-23S rRNA gene ITS regions, we identified four different HaeIII and five different HpaII restriction profiles for bacterial isolates from organic apple cider vinegar. Each type of restriction profile was further analyzed by sequence analysis of the 16S-23S rRNA gene ITS regions, resulting in identification of the following species: Acetobacter pasteurianus (71.90%), Acetobacter ghanensis (12.50%), Komagataeibacter oboediens (9.35%) and Komagataeibacter saccharivorans (6.25%). Using the same analytical approach in conventional apple cider vinegar, we identified only two different HaeIII and two different HpaII restriction profiles of the 16S-23S rRNA gene ITS regions, which belong to the species Acetobacter pasteurianus (66.70%) and Komagataeibacter oboediens (33.30%). Yeasts that are able to resist 30 g/L of acetic acid were isolated from the acetic acid production phase and further identified by sequence analysis of the ITS1-5.8S rDNA- ITS2 region as Candida ethanolica, Pichia membranifaciens and Saccharomycodes ludwigii. This study has shown for the first time that the bacterial microbiota for the industrial production of organic apple cider vinegar is clearly more heterogeneous than the bacterial microbiota for the industrial production of conventional apple cider vinegar. Further chemical analysis should reveal if a difference in microbiota composition influences the quality of different types of apple cider vinegar.
Hard cider production has increased annually by 50% between 2009 and 2014 in the United States while apple (Malus ·domestica) orchards managed exclusively for cider apples are rare. Cider apples have unique flavor, acid, and tannin characteristics suited to only hard cider production. Demand for fruit by cider makers represents an emerging market for apple growers and an opportunity to diversify their production and marketing systems. The goal of this study was to compare the fruit requirements of cider makers with present cider fruit availability in orchards to identify opportunities and challenges for the growth of both industries, and we surveyed cider makers and apple growers. Growers in our study saw a market expansion opportunity in the growth of popularity of hard cider, but present apple prices were identified as a key threat. Cider makers are also expanding their operations, all of those sampled anticipate increasing their production in the next five years, but maintaining adequate fruit supply was identified as a major threat. Cider makers and apple growers have both expressed interest in dualpurpose cultivars that may be sold to the fresh market or for cider making. Apple growers have expressed guarded interest in growing specialty cider cultivars while cider makers have expressed a strong interest in increased production of ciderspecific cultivars. We conclude that there are a number of potentially beneficial opportunities, particularly in increased production of dual-purpose and specialty cider cultivars, as long as price and coordination issues can be resolved.
Based on limited research concerning the aroma of apple ciders and the goal of increasing the utilization of apple pomace, we evaluated the sensory profiles of apple homogenate ciders made with koji, Saccharomyces cerevisiae, or a mixture of both. Sensory analyses demonstrated that ciders made with pure and mixed koji cultures have significantly different physicochemical, aroma and taste profiles compared to ciders made with S. cerevisiae. Aroma compound identification showed that pure and mixed koji cultures produced volatile components in high abundance and contained similar amounts of esters and alcohols compared with S. cerevisiae monocultures. These results suggest that koji cultures could be used to augment the quality of ciders made traditionally with S. cerevisiae alone. The production of apple homogenate ciders using koji cultures could reduce production costs by eliminating the need for added sweeteners and increasing the utilization of apple pomace, adding value to the raw apple product.Practical ApplicationsIn this paper, a cider-making method with koji has been developed, which can make apple cider with apple pomace without adding sweeteners.
To study the role of the indigenous yeast flora in traditional Irish cider fermentations.
Wallerstein laboratory nutrient agar supplemented with biotin, ferric ammonium citrate, calcium carbonate and ethanol was employed together with PCR-restriction fragment length polymorphism analysis of the region spanning the internal transcribed spacers (ITS1 and ITS2) and the 5.8S rRNA gene in the identification of indigenous yeasts at the species level, from traditional Irish cider fermentations. By combining the molecular approach and the presumptive media it was possible to distinguish between a large number of yeast species, and to track them within cider fermentations. The Irish cider fermentation process can be divided into three sequential phases based on the predominant yeast type present. Kloeckera/Hanseniaspora uvarum type yeasts predominate in the initial 'fruit yeast phase'. Thereafter Saccharomyces cerevisiae type yeast dominate in the 'fermentation phase', where the alcoholic fermentation takes place. Finally the 'maturation phase' which follows, is dominated by Dekkera and Brettanomyces type yeasts. H. uvarum type yeast were found to have originated from the fruit. Brettanomyces type yeast could be traced back to the press house, and also to the fruit. The press house was identified as having high levels of S. cerevisiae type yeast. A strong link was noted between the temperature profile of the cider fermentations, which ranged from 22 to 35 degrees C and the yeast strain population dynamics.
Many different indigenous yeast species were identified. The mycology of Irish cider fermentations appears to be very similar to that which has previously been reported in the wine industry.
This study has allowed us to gain a better understanding of the role of indigenous yeast species in 'Natural' Irish cider fermentations.
The acetic acid bacteria (AAB) have important roles in food and beverage production, as well as in the bioproduction of industrial chemicals. In recent years, there have been major advances in understanding their taxonomy, molecular biology, and physiology, and in methods for their isolation and identification. AAB are obligate aerobes that oxidize sugars, sugar alcohols, and ethanol with the production of acetic acid as the major end product. This special type of metabolism differentiates them from all other bacteria. Recently, the AAB taxonomy has been strongly rearranged as new techniques using 16S rRNA sequence analysis have been introduced. Currently, the AAB are classified in ten genera in the family Acetobacteriaceae. AAB can not only play a positive role in the production of selected foods and beverages, but they can also spoil other foods and beverages. AAB occur in sugar- and alcohol-enriched environments. The difficulty of cultivation of AAB on semisolid media in the past resulted in poor knowledge of the species present in industrial processes. The first step of acetic acid production is the conversion of ethanol from a carbohydrate carried out by yeasts, and the second step is the oxidation of ethanol to acetic acid carried out by AAB. Vinegar is traditionally the product of acetous fermentation of natural alcoholic substrates. Depending on the substrate, vinegars can be classified as fruit, starch, or spirit substrate vinegars. Although a variety of bacteria can produce acetic acid, mostly members of Acetobacter, Gluconacetobacter, and Gluconobacter are used commercially. Industrial vinegar manufacturing processes fall into three main categories: slow processes, quick processes, and submerged processes. AAB also play an important role in cocoa production, which represents a significant means of income for some countries. Microbial cellulose, produced by AAB, possesses some excellent physical properties and has potential for many applications. Other products of biotransformations by AAB or their enzymes include 2-keto-L-gulonic acid, which is used for the production of vitamin C; D-tagatose, which is used as a bulking agent in food and a noncalorific sweetener; and shikimate, which is a key intermediate for a large number of antibiotics. Recently, for the first time, a pathogenic acetic acid bacterium was described, representing the newest and tenth genus of AAB.
The objective of this research was to recover and apply the phenolic compounds from apple pomace during the manufacture of cider, aiming to increase bioactivity and improve the sensorial quality. The conditions of solid-liquid extraction process (60% ethanol at 50 °C and 1:20 w/v solid-solvent ratio) were optimized using the response surface method and kinetic study was performed by first order nonlinear model fitting. The addition of the extract was based on the initial total flavonoid content; this generated the following treatments: control must (M0); with the addition of 77 mg/L (M50); and with the addition of 130 mg/L (M100), which produced the respective ciders C0, C50 and C100. The addition of the phenolic extract increased the antioxidant activity by 1.6 and 2.8 times for the M50 and M100 treatments, respectively. Of the individual phenols, the ciders with the addition of extract showed quercetin glycosides, which were initially non-existent. Moreover, the addition of the extract accentuated the color and perceptions of bitterness and astringency without harming the odor quality. Therefore, the phenolic extract from apple pomace is a viable economic alternative for accentuating antioxidant activity and improving the sensorial quality of ciders.
Objectives:
More than 70% of birch pollen-allergic individuals are affected by a cross-allergy from apples. The aim of this study was to determine if an increased polyphenolic content of apples is inversely related to clinical allergic reactions in sufferers.
Methods:
The polyphenolic content of two old and two new apple cultivars was analyzed using high performance liquid chromatography. The in vitro concentration of sulfidoleukotrienes and the CD63 basophil activation of 27 birch pollen sufferers with cross-reactivity to apples were determined with cellular antigen stimulation and basophil activation tests after incubation with different apple cultivars.
Results:
The flesh of old cultivars was characterized by significantly higher total polyphenolic content (86.1 ± 5.5 µg/g) than that of new cultivars (24.7 ± 7.2 µg/g). The concentration of sulfidoleukotrienes and the CD63 basophil activation of old apple cultivars was up to 62% lower than new ones and decreased as the degree of enzymatic browning increased.
Conclusion:
Old apples cultivars are better tolerated than new ones by birch pollen-allergic individuals. The in vitro allergenicity (activation of effector cells) of apples depends on the total polyphenolic content and the degree of enzymatic browning.
Ice cider is a special product made from apple juices enriched by freezing. In this paper, the method of obtaining the ice juices (cryo-extraction and exhaustion) and the year of harvest have been evaluated. For this purpose, a controlled raw apple mixture and an autochthonous Saccharomyces bayanus strain were used throughout the study. Both the enrichment system and the year of harvest significantly influenced the levels of total phenols, sucrose, malic acid, ethyl acetate and 2-phenylethanol. The ciders made by cryo-extraction presented the higher sugar/acidity and sugar/polyphenol ratios. These ciders were more fruity, less astringent and scored better for quality than those obtained by exhaustion. Additionally, a preliminary assay of juice enrichment by cryo-concentration is described. The corresponding ciders presented higher methanol and lower 2-phenylethanol contents than those obtained by the cryo-extraction and exhaustion methods.
Furan, which has been identified as a carcinogenic risk for humans, can be induced in different foods by UV-C light. In this study, we hypothesized that furan was produced by a UV light-induced free radical mechanism and antioxidants could suppress its formation. Our results demonstrated that, by adding antioxidants, such as butylated hydroxyl toluene, ascorbic acid or gallic acid, to simulated juice or apple cider during UV-C treatment, amounts of furan were significantly reduced. For example, the concentration of furan produced in apple cider by UV-C at 9.0 J/cm² was 636 ppb but was less than 20 ppb with 0.25 ppm butylated hydroxyl toluene present, less than 3 ppb with 0.5% (w/v) ascorbic acid, and less than 1.0 ppb with 0.5% (w/v) gallic acid. These findings confirmed that antioxidants can be used as a safe and simple mitigation measure to control furan production in fruit drinks exposed to UV-light.
A GC-FID method for major volatile analysis in cider and wine was validated under the requirements of the ISO/ IEC 17025 regulation using a split mode injection. This method presented a good linearity (R²>0.999, Cm>99%), a wide range of calibration, the maximum random errors for repeatability and intermediate precision were 5% and 8%, respectively, and the maximum limit of quantifi cation and limit of detection were 14.1 mg l-1 and 4.6 mg l-1, respectively. Trueness, expressed as recovery (%), was successfully validated by means of two different methods, standard addition (92-110%) and comparison against reference materials (93-115%). Expanded uncertainty estimated at 95% confi dence level ranged between 11% for methanol and 7% for allyl alcohol. The validated method was successfully applied for the analysis of major volatiles in ciders and wines, and to detect yeast and lactic acid bacteria spoilage.
Machine harvest of ‘Brown Snout’ specialty cider apple (Malus ×domestica) has been shown to provide yield and juice quality characteristics similar to that of hand harvest. In this 2-year study, the sensory perception (color, aroma, flavor, mouthfeel, taste, and aftertaste) of ciders produced from machine-harvested and hand-harvested fruit that were ambient stored (56 °F) 0–4 weeks postharvest were compared using a trained panel and electronic tongue (e-tongue). For nearly all sensory attributes evaluated, the trained panelists scored the 2014 machine-harvested samples higher than the 2014 hand-harvested samples. Some of the key sensory differences included a darker color, a more astringent and heated mouthfeel, and a more sour taste of the machine-harvested samples than the hand-harvested samples. Trained panelists perceived no differences due to the harvest method among the 2015 samples for any of the sensory attributes evaluated. The e-tongue demonstrated good discrimination (index value = 95) of 2014 samples, but poor discrimination (index value = −0.5) of 2015 samples, mirroring the year-to-year variation experienced by the trained panelists. Overall, the e-tongue demonstrated a response to metallic and sour that was more associated with the machine-harvested samples and a response to sweet and umami that was more associated with the hand-harvested samples. These results demonstrate that cider made from machine-harvested fruit can have a different sensory profile than cider made from hand-harvested fruit. A consumer tasting panel should be conducted next to provide an indication of market response to the differing sensory profiles, qualifying the impact of harvest method. Results also indicate that ambient storage (56 °F) of fruit up to 4 weeks may not impact cider sensory attributes; however, cider apple growers should avoid ambient storage of machine-harvested fruit given the significant yield losses demonstrated in previous studies. Variation in cider quality due to year of harvest was most likely a result of differences in the hand-harvest technique between the 2 years, specifically more fruit bruising in 2014 than in 2015, demonstrating the importance of harvesting fully mature fruit with a standard protocol so as to supply a consistent raw material to cider producers. The e-tongue produced variable results compared with trained panelists and more development is needed before it can be incorporated into cider sensory evaluation protocol. © 2018, American Society for Horticultural Science. All rights reserved.
Nursing care and patient education are integral to compliance with dermatologic medical treatments. This column has been developed in partnership with caring nurses dedicated to optimizing patient care through practicum-based education and treatment. This article focuses on apple cider vinegar baths for atopic dermatitis.
Metabolic syndrome is a serious consequence of obesity characterized by increased cardiovascular risk factors such as hypertension, dyslipidemia, and glucose intolerance. While diets enriched with natural antioxidants showed beneficial effects on oxidative stress, blood pressure, and serum lipid composition, diet supplementation with synthetic antioxidants showed contradictive results. Thus, we tested, in this study, whether a daily dosage of Apple Cider Vinegar (ACV) would affect cardiovascular risk factor associated with obesity in high-fat diet (HFD)-induced hyperlipidemic Wistar rats. Obese rats showed increased serum total cholesterol, triglyceride, low-density lipoprotein-cholesterol (LDL-C), very low density lipoprotein (VLDL) and atherogenic index after 6 and 9 weeks of being fed an HFD. Importantly, ACV ameliorated all of these parameters significantly. Oxidative stress already developed after 6 weeks of HFD and was significantly reduced by daily doses of ACV. Oral administration of ACV normalized various biochemical and metabolic changes since it exhibited a very significant (P < .001) reduction in malondialdehyde levels, whereas an increase in thiol group concentrations and antioxidant status (superoxide dismutase [SOD], glutathione peroxidase [GPx], and catalase [CAT] activities and vitamin E concentrations). In addition, a modulation in trace element levels was observed when compared with HFD groups. These findings suggested that HFD alters the oxidant-antioxidant balance, as evidenced by a reduction in the antioxidant enzyme activities and vitamin E level, and enhanced lipid peroxidation. ACV can be beneficial for the suppression of obesity-induced oxidative stress in HFD rats through the modulating antioxidant defense system and reduces the risk of obesity-associated diseases by preventing the atherogenic risk.
In this study, highly reactive endo- and exo-polygalacturonases (PGs) were produced from the tobacco industry wastewater using immobilized Rhizopus oryzae. Compared with free cells, immobilized cells increased enzyme activity 2.8-fold and reduced production time to 24 h by shake-flask production. Moreover, the immobilized cells enabled the semi-continuous production of enzymes through repeated-batch mode for seven consecutive cycles in a scale-up bioreactor. During the first five cycles, the average endo-PG and exo-PG activities reached 307.5 and 242.6 U/ml, respectively. The addition of crude enzyme for the hydrolysis of pectin-containing lignocellulosic biomass under high-gravity conditions increased glucose release 4.2-fold (115.4 vs. 29.0 g/L), compared with hydrolysis using cellulase alone. This process achieves the efficient production of pectin-degrading enzymes, provides a cost-effective method for tobacco wastewater treatment, and offers the possibility to obtain fermentable sugars with high-titer from pectin-containing lignocellulosic biomass, which has important potential for the commercial production of bio-fuels.
Hydroxycinnamic acids and flavonoids in apple juices and ciders were studied using liquid chromatography. Samples were produced from four different Estonian apple cultivars using unripe, ripe and overripe apples, and six different commercial yeasts including Saccharomyces cerevisiae, Saccharomyces bayanus, and Torulaspora delbrueckii strains. Part of the samples was additionally inoculated with malolactic bacteria, Oenococcus oeni. The most notable difference among the samples was the appearance of phloretin in malolactic ciders in comparison to conventional ciders and the juices. Furthermore, the apple cultivars were significantly different in their phenolic contents and compositions. Additionally, ciders and juices made from unripe apples contained more phenolic compounds than the ripe or overripe, but the effect was dependent on cultivar. The commercial yeast strains differed in the release of free HCAs, especially p-coumaric acid, during the yeast fermentation. In ciders inoculated with S. bayanus, the content was higher than in ciders fermented with S. cerevisiae.
A chromatographic method for the separation of volatile compounds in Asturian cider apple juices has been developed. For this separation purpose, a monocationic imidazolium-based ionic liquid bearing a reactive terminal iodine atom was synthesized by a quaternization-anion exchange chemical sequence. Next, the gas chromatography (GC) stationary phase was prepared by covalently linking the imidazolium monolith to the reactive silanol groups of the inner capillary wall at 70 °C. This coated GC column exhibited good thermal stability (290 °C), as well as good efficiency (2000 plates/m) in the separation of volatile compounds from Asturian apple cider juices, and was characterized using the Abraham solvation parameter model. The intra-day and inter-day precision of the chromatographic method was evaluated, obtaining relative standard deviations from 3.7 to 12.9% and from 7.4 to 18.0%, respectively. Furthermore, recoveries from 82.5 to 122% were achieved. Open image in new windowGraphical AbstractCovalent bonding of an ionic liquid to inner column wall led to a great improvement of the separation efficiencies of stationary phases in gas chromatography
Ice cider is a high value specialty product that was developed in Quebec, Canada. It is typically very sweet and has an intense apple taste due to specific production practices. Other fruit wines can be produced at a lower cost, and there is a need for ice cider authentication methods. An experiment was conducted to determine the uniqueness of ice cider in terms of physico-chemistry. Simple laboratory procedures were considered in addition to infrared and fluorescence spectroscopy. One hundred bottles with vintages from 2001 to 2015 were collected. Besides, 11 comparable apple wines (CAW) were selected, including quiet, fortified, aperitif and fire ciders. In addition, 36 ‘laboratory wines’ (LW) were prepared by mixing various juices, ethanol and sugars. A linear discriminant analysis with variable selection was performed to classify products as ice cider or not. Input variables were results from laboratory test or scores from principal component analysis of spectra. Ninety four percent of ice ciders and 45% of CAW were correctly identified by simple laboratory tests but the method was not specific as 6 LWs were confused with ice cider. Infrared spectroscopy or fluorescence at 280, 330, 415 and 460 nm excitation wavelengths allowed for correct classification of 95% of samples and all LW. Infrared was poor at distinguishing CAW (45% correct classification) while fluorescence was better (73% correct classification). Measuring intrinsic fluorescence represents an opportunity for a simple and low cost for the authentication of ice cider.
Varietal base ciders were produced from three varieties of dessert apples (‘Pink Lady®’, ‘Royal Gala’ and ‘Red Delicious’) at pre-commercial, commercial and post-commercial harvest timings. Rapid analytical methods were used to categorise the base ciders, and data analysed using principal component analysis (PCA). The titratable acidity of apple must was significantly higher for the pre-commercial harvest fruit for both the ‘Royal Gala’ and ‘Red Delicious’ varieties. The base cider phenolic content was highest in the pre-commercial harvest fruit for all varieties. ‘Red Delicious’ had the highest total phenolics as determined by spectral analysis and supported by the classification provided by the PCA analysis. The spectral fingerprints of the ciders showed two main peaks at approximately 280 nm and 320 nm indicating phenolic concentrations. Studies analysing characteristics of dessert apple varieties with relevance for cider production will allow for informed decision making for both apple producers and cider makers.
This work aimed to find a rational nutrient feeding strategy for cider vinegar fermentation based on adequate information on the nutritional requirement of acetic acid bacteria. Through single nutrient lack experiment assay, necessary nutrient recipe for Acetobacter pasteurianus CICIM B7003 in acetous fermentation was confirmed. Compounds from the essential nutrient recipe were tested further to find out the key substrates significantly influencing cider vinegar fermentation. The findings showed that aspartate, glutamate, proline and tryptophan should be considered in detail for optimizing nutritional composition of cider. Finally, a nutrient feeding strategy that simultaneously adds proline, glutamate, aspartate and tryptophan to form final concentrations of 0.02 g/L, 0.03 g/L, 0.01 g/L and 0.005 g/L in cider was achieved by orthogonal experiment design. Comparing to the original fermentation, the yield of acetic acid from alcohol reached 93.3% and the concentration of most volatile flavor compounds increased with the rational nutrient feeding strategy.
The role of pectin in membrane fouling during cold MF of apple cider was investigated. Clarified apple juice with four different concentrations of pectin was subjected to cold MF, at pore sizes above 0.45 μm. The experimental data shows that pectin plays a significant role in membrane fouling, and its fouling effect increased with increasing concentration. The association of pectin with polyphenols and proteins, which results in colloidal haze particles with low surface electrical charge, seems to be the major factor in fouling during cold MF of apple cider. Depectinization was beneficial to MF with pore sizes below 0.45 μm, for which fouling is dominated by cake layer formation. Depectinization had a negative effect on MF flux for pore sizes above 0.8 μm, since the size reduction of haze particles accentuated pore constriction and blockage, which dominate fouling in large pore MF. These findings have practical implications for the development of efficient, commercially viable, cold MF processes for minimally processed apple cider.
Vinegars are liquid products produced from the alcoholic and subsequent acetous fermentation of carbohydrate sources. They have been used as remedies in many cultures and have been reported to provide beneficial health effects when consumed regularly. Such benefits are due to various types of polyphenols, micronutrients and other bioactive compounds found in vinegars that contribute to their pharmacological effects, among them, antimicrobial, antidiabetic, antioxidative, antiobesity and antihypertensive effects. There are many types of vinegars worldwide, including black vinegar, rice vinegar, balsamic vinegar and white wine vinegar. All these vinegars are produced using different raw materials, yeast strains and fermentation procedures, thus giving them their own unique tastes and flavours. The main volatile compound in vinegar is acetic acid, which gives vinegar its strong, sour aroma and flavour. Other volatile compounds present in vinegars are mainly alcohols, acids, esters, aldehydes and ketones. The diversity of vinegars allows extensive applications in food.
Optimization of a multivariate calibration process has been undertaken for a Visible-Near Infrared (400-1100 nm) sensor system, applied in the monitoring of the fermentation process of the cider produced in the Basque Country (Spain). The main parameters that were monitored included alcoholic proof, L-lactic acid content, glucose+fructose and acetic acid content. The Multivariate calibration was carried out using a combination of different variable selection techniques and the most suitable pre-processing strategies were selected based on the spectra characteristics obtained by the sensor system. The variable selection techniques studied in this work include Martens Uncertainty test, interval Partial Least Square Regression (iPLS) and Genetic Algorithm (GA). This procedure arises from the need to improve the calibration models prediction ability for cider monitoring.
The aim of this study was to identify the main amino acids responsible for the production of esters in ciders. The experiments were carried out in apple must and synthetic must. The amino acids were analysed by high-performance liquid chromatography and the volatile compounds by gas chromatography. Aspartate, asparagine and glutamate positively influenced the production of esters in the cider models and were used in the experiments with mixtures. The response surface generated by the proposed model yielded two regions that maximized the production of esters. In addition, the combination of aspartate and glutamate predicted a higher production. The optimal suggested concentrations were 43.4% of aspartate and 56.6% of glutamate for 120mg/L of total nitrogen. The apple must supplemented with these two amino acids resulted in four times more esters than in the same cider without supplementation, demonstrating the effectiveness of the proposed model.
Multiple binary mixtures of different kinds of vinegars have been analyzed through UV-Vis absorption. Two types of mathematical models (multiple linear regression (MLR) and artificial neural network (ANN)) have been employed to identify and quantify the components of such blends. Six different vinegars were used to prepare these mixtures, each one with a particular botanical origin: white wine, red wine, apple cider, apple, molasses, and rice. The best results have been attained with the ANN based models, offering mean estimation error values averages of 1% (v/v) and mean correlation coefficients (R2) over 0.99. This model is adequate to perform the estimation and achieve an accurate and reliable tool. Nevertheless, although the MLR models provide worse results (0.88 in terms of R2 and 5% v/v error), they can be used depending on the application and required accuracy.
Unfiltered vinegar samples collected from three oxidation cycles of the submerged industrial production of each, red wine and organic apple cider vinegars, were sampled in a Slovene vinegar producing company. The samples were systematically collected from the beginning to the end of an oxidation cycle and used for culture-independent microbial analyses carried out by denaturing high pressure liquid chromatography (DHPLC) and Illumina MiSeq sequencing of 16S rRNA gene variable regions. Both approaches showed a very homogeneous bacterial structure during wine vinegar production but more heterogeneous during organic apple cider vinegar production. In all wine vinegar samples Komagataeibacter oboediens (formerly Gluconacetobacter oboediens) was a predominating species. In apple cider vinegar the acetic acid and lactic acid bacteria were two major groups of bacteria. The acetic acid bacterial consortium was composed of Acetobacter and Komagataeibacter with the Komagataeibacter genus outcompeting the Acetobacter in all apple cider vinegar samples at the end of oxidation cycle. Among the lactic acid bacterial consortium two dominating genera were identified, Lactobacillus and Oenococcus, with Oenococcus prevailing with increasing concentration of acetic acid in vinegars. Unexpectedly, a minor genus of the acetic acid bacterial consortium in organic apple cider vinegar was Gluconobacter, suggesting a possible development of the Gluconobacter population with a tolerance against ethanol and acetic acid. Among the accompanying bacteria of the wine vinegar, the genus Rhodococcus was detected, but it decreased substantially by the end of oxidation cycles.
Voltammograms recorded on the glassy carbon electrode (GCE) may be a chemical fingerprints of food samples, enabled distinguishing the origin of the considered products. In this work the objects of the study was 5 Polish ciders of various brands. For each sample 10 scans were recorded by DPV in the potential range between -0.2 and 1.0 V in Britton-Robinson buffer at pH 2.0. The signals preprocessing realized by baseline correction with 4-th degree polynomial and normalization (in 0 to 1 interval), performed to reduce problems with insufficient signal's repeatability associated with mechanical renovation of the electrode surface before each measurement. The PLS-DA classification models were built using the training set and then validated using the samples absent in the learning process. The final multi-class model with optimized complexity enables classification of the ciders with 100% sensitivity and specificity, with the exception of one cider, where specificity was 95% (for validation set).
The identification of vinegars produced from six different raw materials (red wine, white wine, cider, apple, molasses, and rice) in blends has been accomplished through their UV-Vis spectra and different mathematical models: partial least squares discriminant analysis (PLS-DA) and artificial neural networks (ANNs). The registered spectra were mathematically treated following a linear (PLS-DA) approach and a non-linear one (ANN) based on multilayer perceptron models with different training functions. The average correct classification rate of a series of comparable internal validations was around 55% and 90%, for the PLS-DA and the ANN models respectively, which heavily favors the non-linear approach. Therefore, an accurate chemometric tool with the ability to detect specific vinegars in mixtures in an inexpensive and straightforward fashion has been designed and optimized.
This research was conducted to evaluate the impact of co-fermentation with Saccharomyces cerevisiae and Williopsis saturnus var. mrakii on the volatile profile of cider. Cider co-fermentation was carried out by co-inoculating S. cerevisiae and W. saturnus var. mrakii at a ratio of 1:100. Changes in yeast cell population, total soluble solid content (degrees Brix [°Bx]), and pH were monitored. Volatiles were analysed using headspace solid-phase microextraction/gas chromatography–mass spectrometry/flame ionization detector (HS-SPME/GC-MS-FID). A diverse group of volatiles, including fatty acids, alcohols, aldehydes, esters and ketones, were identified, among which alcohols and esters were the predominant compounds. Although most of these compounds showed similar dynamics of change, the final concentrations of some volatiles differed significantly between single-culture and co-culture fermentations. Volatiles that were indigenous to apple juice decreased during fermentation, while production of isoamyl acetate, 2-phenylethyl acetate, ethyl acetate, ethyl decanoate, ethyl dodecanoate and ethyl octanoate varied significantly among the monocultures and co-culture. Co-fermentation by S. cerevisiae and W. saturnus resulted in a more complex volatile profile, which could impact on the aromatic characteristics of cider, thus representing a novel way to modulate flavour.
This study was conducted to examine the influence of the following apple juice treatments on different parameters of cidermaking process: sulphiting (50 mg/L of total S02), clarification with pectolytic enzymes (Ultrazym 100 G, 3g/hL), and bentonite fining (lOOg/hL). The different treatments slowed down alcoholic fermentation, the greatest effect being found for the combination of the three treatments. With respect to malolactic fermentation, must sulphiting, with or without the other two treatments, delayed this process, which took place after alcoholic fermentation. The low levels of lactic acid bacteria during this period can explain this delay. The only treatment that had any significant influence on volatile acidity was sulphiting, either on its own or in combination with the other treatments. Thus lower acetic acid levels were detected in ciders treated with SO2.
The word vinegar has been in use in the English language since the 14th century, when it arrived in the British Isles from
the French vinaigre, a word that simply means ‘sour wine’, and that came in turn from the Latin vinum acre, ‘sour wine’ or,
more commonly, vinum acetum, ‘wine vinegar’.
Apple vinegar or cider vinegar (CV) is made with apple juice or concentrated apple juice (CAJ) through a double fermentation:
alcoholic and acetic. Cider vinegar is extensively used in several countries including Austria, the UK, the USA and Switzerland
(Ebner, 1982; Lea, 1988).
The aim of this study was to evaluate the potential of integrated membrane processes for the clarification and the concentration of apple juice, taking into account the impact on the product quality. The fresh apple juice, with a total soluble solids (TSS) content of about 12°Brix was previously clarified by combined application of fining agents (gelatin and bentonite) and ultrafiltration (UF) through 10 kDa or 100 kDa molecular weight cut-off (MWCO) membranes on laboratory scale. The clarified juice was then concentrated by osmotic distillation (OD), membrane distillation (MD), coupled operation of OD and MD or by conventional thermal evaporation up to 65°Brix. The effect of different clarification and concentration processes on formation of 5-hydroxymethylfurfural (HMF), retention of bioactive compounds (phenolic compounds, organic acids, glucose, fructose and sucrose) and their efficiency in preserving natural color and aroma (trans-2-hexenal, the most relevant compound in apple juice aroma) were evaluated in order to maintain a high quality product. The new membrane-based concentration techniques were very efficient since the product characteristics were very similar to that of the initial apple juice especially regarding the retention of bright natural color and pleasant aroma, which are significantly lost during thermal evaporation. Furthermore, among all the concentration treatments applied, only thermally evaporated samples resulted formation of HMF. Phenolic compounds, organic acids and sugars were very stable against all concentration processes, including thermal evaporation. Coupled operation of OD and MD reduced trans-2-hexenal losses drastically tending towards that of the initial juice and hence can be proposed as the most promising alternative to conventional thermal evaporation technique.
This paper studies the clarification of vinegars (white, rosé and red) by cross-flow microfiltration on an industrial scale. The reduction in turbidity for the three kinds of vinegars was notable: for filtered vinegars it was less than 0.5 NTU. The reduction of total solids in suspension was complete. These results show the utility of using microfiltration to simultaneously clarify and cold sterilise vinegar. The effect of microfiltration on colour and polyphenol content was acceptable. The colour reduction, expressed as a decrease in modified colour intensity, was practically negligible for white vinegars, 11% for rosé vinegar and 37% for red vinegar. The reduction in polyphenol content was less than 15% in all vinegars, and was largest for red vinegar, followed by rosé and finally white vinegar. The polyphenolic profile of the filtered vinegars is quite similar to that of the initial vinegar. The reduction in benzoic and hydroxycinnamic acids identified was less than 10% for all vinegars. However, the reduction in procyanidin B2 was total for rosé and red vinegars.
Wine vinegar is produced in most Mediterranean countries and extensively used as a condiment, acidifying and food preserving agent. Traditional production requires maturation in wood for many years to obtain a high acetic degree and the resulting product is relatively expensive. New technologies are being designed to overcome this difficulty with the objective of producing vinegars with a similar quality and at the same time less expensive. These methods of production involve the use of submerged bacterial culture and a continuous aeration system. Recent research is focussed in improving yield and quality of the final product.
Association of Manufacturers and Formulators of Enzyme Products
AMFEP. 2018. Association of Manufacturers and Formulators of Enzyme Products (https://
amfep.org).
Chemistry and Technology of Soft Drinks and Fruit Juices, Third Edition
- P R Ashurst
Ashurst, P.R. (Ed.). 2016. Chemistry and Technology of Soft Drinks and Fruit Juices, Third
Edition. Oxford: John Wiley & Sons, Ltd.
B&P. 2018. B&P Engineering (www.engineering-bp.com).
- Bucher
Bucher. 2018. Bucher Unipektin AG, Switzerland (www.bucherunipektin.com).