Cider Quality Research Articles

Cider Terroir: Influence of Regionality on Australian Apple Cider Quality

Understanding how regionality influences the key characteristics of cider will assist the industry to produce a premium and consistent quality product. Three dessert apple varieties were sourced from three (minimum) orchards per region from nine major growing regions across Australia over two seasons. Ciders produced from these apples were analysed for base quality characteristics, including total phenolic content (TPC), pH, total soluble solids (TSS) and titratable acidity (TA). Across both seasons, region had a significant influence on TPC, with the region model explaining approximately 25% of the variation in TPC. TSS and TA were significantly influenced by an interaction between variety and region, with the model accounting for approximately 60% and 75% of the variation, respectively, over both seasons. An interaction between variety and region influenced pH results in the first season, with only mean effects in the second season. A climate model was developed using average rainfall data and growing degree days (GDDs). Differences in climate accounted for most, but not all, of the regional variation observed in cider quality measurements. These results demonstrate that the apple growing region can significantly impact the resulting cider quality. Such findings are critical for supporting cider producers to make informed decisions when sourcing fruit.

Enhancing cider quality through co-fermentation with acid protease and esterase-producing Metschnikowia species and Saccharomyces cerevisiae.

To date, cider production has primarily relied on Saccharomyces cerevisiae. Introducing novel non-Saccharomyces yeasts can enhance the diversity of cider properties. Among these, the Metschnikowia genus stands out for its ability to produce hydrolytic enzymes that may impact the sensorial and technological properties of cider. This study focused on evaluating the impact of three Metschnikowia species - Metschnikowia koreensis (Mk), M. reukaufii (Mr), and M. pulcherrima (Mp) - which exhibit acid protease and esterase activity, on the quality enhancement of cider. The research findings indicate that the overall quality of cider produced through co-fermentation with these species surpassed that of cider fermented with mono-fermentation of S. cerevisiae (Sc). The cider fermented with the Sc + Mk combination exhibited the lowest levels of harsh-tasting malic acid and higher levels of softer lactic acid. Sensory array analysis also demonstrated that the Sc + Mk fermented cider exhibited high sensor response values for compounds contributing to a complex overall olfactory composition and richness. Furthermore, the Sc + Mk fermented cider exhibited the highest total quantity and variety of volatile organic compounds (VOCs). Specifically, the concentrations of phenethyl alcohol, 3-methyl-1-butanol, ethyl octanoate, and decanoic acid were notably elevated in comparison with other groups. This study illustrates that Metschnikowia species, particularly M. koreensis, show significant potential as starters for cider due to their various technological properties, including acidity modulation, aroma enhancement, and color improvement. The findings of this study provide a foundation for improving cider quality by co-fermenting S. cerevisiae with innovative starter cultures. © 2024 Society of Chemical Industry.

Effect of co-inoculation of Saccharomyces and non-Saccharomyces yeasts and nutrients addition during malolactic fermentation on apple cider composition

Apple cider production is a complex fermentation process that involves the conversion of apple juice into cider through the actions of yeast and malolactic bacteria. This study aimed to investigate the effects of the co-inoculation of Saccharomyces and non-Saccharomyces yeasts, as well as nutrient supplementation in the presence of malolactic bacteria Oenoccocus oeni on the composition of apple cider. The amino acid profile of the samples was not significantly influenced by the addition of lactic bacteria or nutrients in cider processing. The highest ester content was recorded in the single yeast strain fermented ciders (55.32%–88.13%). This increase was visible also for the malolactic ciders, independent from nutrient supplementation. Co-inoculated Saccharomyces and Torulaspora delbrueckii ciders showed increased higher alcohols contents, both after the alcoholic (42.66%–53.51%) and malolactic fermentations (42.81%–65.94%). Following the hydroxycynnamic acids class (141.47–327.44 mg/L), flavonoids (114.81–253.44 mg/L) were the second most abundant class of phenolic compounds in ciders, which generally registered a considerable increase following malolactic fermentation. The sour/acidic taste was the most prevalent sensory attribute of the cider. Lower values were recorded for sweet, bitter, and astringent. The strongest apple aroma was perceived in the co-inoculated Saccharomyces and T. delbrueckii yeast strains. The co-fermentation of Saccharomyces and Torulaspora delbrueckii yeasts led to increased levels of desirable aroma compounds, contributing to a more complex and appealing sensory profile, while the nutrient supplementation provided an improved malolactic fermentation efficiency and overall cider quality.

Effects of Torulaspora delbrueckii and Saccharomyces cerevisiae Co-Fermentation on the Physicochemical and Flavor Compounds of Huaniu Apple Cider.

The effects of different fermentation methods utilizing Torulaspora delbrueckii 1004 and Saccharomyces cerevisiae 32169 on the physicochemical properties, organic acid content, polyphenol and flavonoid concentrations, antioxidant activity, and volatile aroma compounds of Huaniu apple cider were investigated in this study. Employing methods of single inoculation, co-inoculation, and sequential inoculation, it was found that sequential fermentation exhibited strong fermentative power in the initial stages, effectively reducing the content of soluble solids and achieving a balanced composition of malic, succinic, and citric acids while maintaining a lower titratable acidity. Sequential inoculation was observed to significantly enhance the total polyphenols and flavonoids, as well as the antioxidant capacity (p < 0.05). Specifically, in the synthesis of volatile aroma compounds, sequential inoculation significantly enhanced the richness and diversity of the Huaniu apple cider's aromas, particularly in terms of the concentration of ester compounds (p < 0.05). Principal component analysis further confirmed the superiority of sequential inoculation in terms of aroma component diversity and richness. The findings of this study suggest that sequential inoculation of fermentation with non-Saccharomyces and S. cerevisiae is an effective strategy for optimizing the flavor characteristics of Huaniu apple cider, offering valuable theoretical support and practical guidance for enhancing cider quality and fostering the development of new products.

Impact of Pure, Co-, and Sequential Fermentations with Hanseniaspora sp. and Saccharomyces cerevisiae on the Volatile Compounds of Ciders

Pure, co-, and sequential fermentations of Hanseniaspora uvarum, H. guilliermondii, and Saccharomyces cerevisiae strains were evaluated to improve the aromatic quality of ciders. In sequential fermentations, Hanseniaspora strains were used as starter, followed by S. cerevisiae inoculation succeeding one, two, and three days of fermentation. Kinetics, physicochemical parameters, and volatile compounds were assessed during 10 days of fermentation. The headspace technique was used to capture the volatile compounds from the ciders obtained in each experiment and analyzed by gas chromatography. Fermentations with pure strains of Hansenisaspora sp. showed a high population (&gt;1010 CFU/mL) but had a low fermentation rate (2.3–3.8 CO2 g/L/d), low consumption of amino acids (20–40 mg/L) with a high residual content, high sugar consumption (80–90 g/L), and low alcohol content (&lt;2.0% v/v). The H. uvarum strain produced a notably high ester content (245 mg/L). In the co-fermentations, H. guilliermondii with S. cerevisiae highlighted a significant production of higher alcohols, similar to that produced by S. cerevisiae alone (152–165 mg/L). In general, the maximum fermentation rate of the sequential inoculations was lower than co-fermentations but showed low residual nitrogen content (&lt;69 mg/L) and good conversion of sugars into ethanol (4.3–5.7% v/v). The highest concentrations of volatile compounds were observed in treatments involving the two non-conventional strains: H. uvarum with S. cerevisiae inoculation after three days (564 mg/L) and H. guilliermondii after just one day (531 mg/L) of fermentation. These differences stemmed from the metabolic activity of the strains. H. uvarum was influenced by the presence of Saccharomyces, whereas H. guilliermondii did not exhibit this effect. Thus, a pure H. uvarum inoculum has the potential to produce a demi-sec cider with low alcohol content and high content of esters, contributing to a fruity aroma. In addition, ciders with sequential inoculation were the most promising for dry cider processing concerning fermentation parameters and bioaroma enrichment.

Assessing the Impact of Simultaneous Co-Fermentation on Malolactic Bioconversion and the Quality of Cider Made with Low-Acidity Apples

This study investigated the synergistic effects of combining Saccharomyces cerevisiae and Oenococcus oeni during the alcoholic fermentation of a low-acidity cider. The initial population of indigenous wild lactic acid bacteria (LAB) in the apple must was 104 CFU/mL. Alcoholic fermentations were carried out without (Cider I) and with (Cider II) the O. oeni inoculation at 105 CFU/mL. As S. cerevisiae grows, a declining trend was observed in indigenous and inoculated LAB populations. While the wild LAB exhibited higher sensitivity than O. oeni, they were not eliminated during alcoholic fermentation. The addition of O. oeni impacted the growth and metabolic activity of S. cerevisiae. The bioconversion of malic acid into lactic acid predominantly occurred during the growth phase (43–66%) and stationary phase (4–27%). The resurgence of O. oeni following alcoholic fermentation significantly impacted the production of volatile compounds. After 20 days of fermentation, Cider II displayed a twofold increase in these compounds, resulting in a more favorable sensory profile according to evaluators. Consequently, malolactic fermentation (MLF) coincided with alcoholic fermentation, leading to a reduction in malic acid content. Furthermore, post alcoholic fermentation, MLF positively enhanced the aromatic quality of low-acid cider made from apples with low acidity.

Multivariate statistical visualisation and modelling of GC–MS data for sensory quality prediction of flavoured cider as influenced by storage time and temperature

It is important to cider producers to ensure the optimal quality of their products directly after production, and after extended shelf life. Quality assessments usually involve regular and continuous sensory evaluation conducted by trained panels. The competitive cider production environment necessitates extensive sensory analysis for new product launches, as part of quality control of existing products and during the production process. This could potentially lead to panel fatigue, less accuracy in sensory evaluation and delays in product launches. This paper describes the development of a partial least squares (PLS) model for the prediction of cider quality based on multivariate correlation of sensory and gas chromatography-mass spectroscopy (GC–MS) volatile compound profile data of a flavoured cider. Clear differences between cider samples of various batches and storage conditions could be visualised using principal component analysis (PCA). However, the developed PLS model was able to predict the commercial cider’s quality irrespective of differences in batch, storage temperature or storage time. The main compounds that are strongly associated with sensory quality and its decline during shelf-life storage were identified. This model is the first quality prediction model to be developed for South African flavoured cider which could be used to facilitate fast, consistent and accurate quality assessment in the high-pressure cider production and trade environment. Furthermore, since the model captures the sensory data obtained from a trained technical panel, it can be used to facilitate the calibration of sensory panels across production sites, reduce product development time and better optimise processes that impact sensory quality.

In-depth exploration on the effects of organic nitrogen addition during different fermentation periods on the quality of cider

Nitrogen is an essential element for the growth and metabolism of Saccharomyces cerevisiae, and has a great impact on the quality of cider. In this study, the effects of organic nitrogen addition at different stages of fermentation process on the quality of cider were systematically explored. The main projects included the analysis of fermentation rate, yeast growth, organic acids, amino acids, and volatile aroma compounds. The results indicated that organic nitrogen addition speeded up fermentation rate and shortened fermentation time. The organic nitrogen addition before fermentation and at the early stationary phase altered the composition of organic acids in cider. Moreover, with the addition of organic nitrogen at three stages of fermentation (pre-fermentation, logarithmic and stable phases of yeast growth), the total concentrations of volatile aroma substances in ciders were 10.57 mg/L, 11.97 mg/L and 11.05 mg/L respectively, which were all significantly higher than that in control group (9.69 mg/L). A close relationship between free amino acids consumed during fermentation and volatile aroma compounds produced was revealed by partial least-squares regression analysis. Overall, this study provided a new strategy for cider quality improvement by evaluating the effects of organic nitrogen on the aroma composition of cider.

Quality Improvement in Apple Ciders during Simultaneous Co-Fermentation through Triple Mixed-Cultures of Saccharomyces cerevisiae, Pichia kudriavzevii, and Lactiplantibacillus plantarum.

This study explored the effect of the combination of Saccharomyces yeast, non-Saccharomyces yeast (Pichia kudriavzevii), and Lactiplantibacillus plantarum during cider fermentation on physicochemical properties, antioxidant activities, flavor and aroma compounds, as well as sensory qualities. Ciders fermented with the triple mixed-cultures of these three species showed lower acid and alcohol content than those fermented with the single-culture of S. cerevisiae. The antioxidant activities were enhanced by the triple mixed-culture fermentation, giving a higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate and total antioxidant capacity; specifically, the SPL5 cider showed the highest DPPH radical scavenging rate (77.28%), while the SPL2 gave the highest total antioxidant capacity (39.57 mmol/L). Additionally, the triple mixed-culture fermentation resulted in improved flavor and aroma with a lower acidity (L-malic acid) and higher aroma compounds (Esters), when compared with the single-culture fermented ciders (Saccharomyces cerevisiae); more specifically, the SPL4 cider resulted in the highest total flavor and aroma compounds. In addition, sensory evaluation demonstrated that ciders produced using the triple mixed-cultures gained higher scores than those fermented using the single-culture of S. cerevisiae, giving better floral aroma, fruity flavor, and overall acceptability. Therefore, our results indicated that the triple mixed-cultures (S. cerevisiae, P. kudriavzevii, and L. plantarum) were found to make up some enological shortages of the single S. cerevisiae fermented cider. This study is believed to provide a potential strategy to enhance cider quality and further give a reference for new industrial development protocols for cider fermentation that have better sensory qualities with higher antioxidant properties.

Research on the Effect of Simultaneous and Sequential Fermentation with Saccharomyces cerevisiae and Lactobacillus plantarum on Antioxidant Activity and Flavor of Apple Cider

The study examined the effect of Lactobacillus plantarum together with Saccharomyces cerevisiae on cider quality through simultaneous and sequential inoculation strategies to evoke malolactic fermentation. The antioxidant activities and flavor compound profiles of apple ciders fermented with mixed cultures of commercial wine yeast (S. cerevisia SY) and autochthonous bacteria (L. plantarum SCFF107 and L. plantarum SCFF200) were assessed. The antioxidant ability results indicated that apple ciders fermented with the simultaneous inoculation method had a higher DPPH radical scavenging rate and total antioxidant capacity, especially for SIL107 cider (simultaneous inoculation with S. cerevisiae SY and L. plantarum SCFF107), which exhibited the highest DPPH free radical scavenging activity (78.14% ± 0.78%) and the highest total antioxidant ability (255.92 ± 7.68 mmol/L). The results showed that ciders produced by mixed inoculation with L. plantarum improved flavor because of their higher contents of volatiles such as esters and higher alcohols and higher contents of non-volatile compounds like organic acids and polyphenols in comparison with the single culture of S. cerevisiae, especially for the simultaneous inoculation method. In addition, irrespective of the inoculation mode, compared to the single culture of cider, L-malic acid degraded dramatically in the presence of L. plantarum during alcoholic fermentation, accompanied by increases in lactic acid. What is more, sensory evaluation results demonstrated that ciders produced by mixed cultures gained higher scores than ciders fermented by the single culture of S. cerevisiae, especially in the simultaneous inoculation mode, in terms of the floral, fruity, and overall acceptability of the cider. Therefore, our results indicated that simultaneous inoculation with L. plantarum was found to compensate for some enological shortages of single S. cerevisiae fermented ciders, which could be a potential strategy to enhance the quality of cider products.

Biotechnological Modification of Cider Brewing Processes for the Enhanced Production of 2-Phenylethanol

Consumers of Australian cider are currently trending towards higher-quality cider products. As a result, boutique and craft cider breweries are expected to experience a period of growth over the next five years. Supporting this trend and subsequent growth is paramount to rebuilding the cider industry post-COVID-19. Many current practices and procedures, such as must clarification and biomass reduction in cider brewing, have been adapted from the beer and wine industry. While these practices are beneficial to the quality of cider and often promote the production of favourable volatile organic compounds (VOCs), the targeted enhancement of specific VOCs has not been achieved. This work investigates the specific enhancement of 2-phenylethanol (2-PE), which is known to improve the organoleptic properties of cider and provide potential health benefits through its antioxidant properties. The effect of three levels of biomass reduction (90%, 80%, and 0%) and five levels of L-phenylalanine (L-phe) saturation (0.5, 1.0, 1.5, 2.0, and 2.5 g L−1) for the enhanced production of 2-PE during cider fermentation were investigated. A high-performance liquid chromatography method was developed to accurately quantify the concentration of both 2-PE and L-phe, with a root-mean-square deviation (RSMD) of 0.41% and 1.60%, respectively. A significant increase in 2-PE production was achieved for all treatments, with 2-PE levels up to two orders of magnitude higher than respective controls. The highest 2-PE production was achieved by a moderate (80%) biomass reduction at a 2.5 g L−1 L-phe spike. Additionally, the VOC profile of several of the ciders was quantitively determined, and subsequent data underwent extensive chemometric analysis. Principle component analysis (PCA) showed that 2-PE and its derivatives (2-phenylethyl pivalate and phenylacetaldehyde) were correlated with the 80% biomass reduction treatment at the highest L-phe spike. Additionally, it was observed that several acids and alkanes were negatively correlated with the production of 2-PE and its derivatives. Additionally, hierarchical cluster analysis (HCA) showed clustering between the 80% and 90% biomass reduction treatments at several L-phe spike concentrations. However, the 0% biomass reduction treatments only showed similarity with other treatments with 0% biomass reduction. This work provides insight into the production of 2-PE during apple cider fermentation while building the foundation for more targeted biotechnological production of favourable compounds to improve cider quality.

A Preliminary Study of Yeast Strain Influence on Chemical and Sensory Characteristics of Apple Cider

During the fermentation of apple juice, yeast metabolism creates complex biosynthetic pathways which produce a range of compounds responsible for the organoleptic qualities of cider. In this study, basic cider quality parameters were measured to investigate the influence of six yeast strains on cider made from three apple varieties (‘Pink Lady’, ‘Sturmer’, and ‘Bulmer’s Norman’). Measurement of pH, titratable acidity, and total phenolic content revealed that yeast can influence cider attributes, albeit variety and season dependent. Descriptive sensory analysis using a trained sensory panel was conducted on cider made from ‘Pink Lady’ apples and the same six yeast strains. The sensory panel significantly differentiated the yeast strains on the attributes of ‘fresh apple’, ‘earthy’ and ‘pear’. Identifying the variety specific influence of individual yeast strains on chemical and sensory characteristics of apple cider will provide cider makers with an enhanced understanding when choosing yeast strains.

Revealing the co-fermentation of Saccharomyces cerevisiae and Schizosaccharomyces pombe on the quality of cider based on the metabolomic and transcriptomic analysis

This study aimed to explore the interaction between S. cerevisiae and S. pombe on the quality of cider fermentation based on metabolic characteristics and transcriptional changes in pure and mixed cultures. The relatively high fermentation temperature (28 °C) was beneficial to the growth of yeasts and the acceleration of fermentation progress, while ensuring safety and quality of the cider. Additionally, the co-fermentation degraded malic acid to reduce the acidity, adjusted the content of polyphenols to decrease the bitterness, and improved the diversity and richness of volatile compounds. The transcriptomic analysis revealed that most of differentially expressed genes in co-fermentation process were mainly enriched in the carbohydrate and amino acids metabolism, including TCA cycle, pyruvate metabolism, glycine, serine and threonine metabolism when compared to the other two single fermentation groups. The results provided the useful knowledge for the manipulation of fermentation process with S. pombe and S. cerevisiae in cider.

Insight into the characteristics of cider fermented by single and co-culture with Saccharomyces cerevisiae and Schizosaccharomyces pombe based on metabolomic and transcriptomic approaches

This study aimed to explore the effect of single and co-culture with Saccharomyces cerevisiae and Schizosaccharomyces pombe on the quality of cider. It was found that the interaction effect was observed in co-culture fermentation (CF) of cider with S. cerevisiae CICC 31084 and S. pombe CICC 1760. Meanwhile, aroma and taste quality of CF was significantly improved involving increase of fruity and floral aroma, which might result from the balance of esters, higher alcohols and terpenes. Moreover, the umami intensity of CF was enhanced, and the taste of sourness and astringency became weaker, which could be due to the higher content of umami amino acid and deacidification of malate. Additionally, a combined metabolic and RNA sequencing analyses revealed a clearer association between flavor quality of cider and gene expression of yeasts. Bioinformatic analysis revealed that the varying genes and metabolites were mainly involved in pathways of carbohydrate, amino acids, energy and terpenes backbone metabolism. Finally, a metabolic pathway visualized the changes of significantly changed metabolites and differentially expressed genes in single and co-culture ciders. This study provided new insights into cider production and facilitated the application of co-culture fermentation technology in fruits cidermaking.

Meta‐analysis of apple (Malus × domestica Borkh.) fruit and juice quality traits for potential use in hard cider production

Societal Impact StatementThe production of hard cider is a burgeoning industry in North America. However, traditional European cider‐specific apples are largely unsuitable for production in modern systems and have not been widely adopted. Evaluation of the biochemical variability in apples can provide a better characterization of varieties for use in hard cider production. Many varieties exhibited extensive variability in biochemical traits. Varieties with high phenolics and acidity displayed greater plasticity of these traits between seasons, which supports the concept of “vintage quality” and opens new marketing opportunities. This study provides valuable insight for apple producers to integrate cider‐specific and nonspecific varieties into their production systems.Summary The North American fermented beverage market has undergone extensive growth in the fermented apple juice (hard cider) sector over the last decade. Traditional hard cider producing regions such as England, France, and Spain have historically utilized cider‐specific apples that have desirable balances between sugar, organic acid, and phenolics. However, in North America, culinary apples (lower acidity and phenolics) are predominantly used, and information distinguishing the varieties with novel use for hard cider production is lacking. In this study, we evaluated variation of four major apple biochemical traits (total soluble solids, pH, titratable acidity, and total phenolics) as they relate to use for hard cider production by using a meta‐analysis approach. We analyzed the variation in cider quality traits across 47 published works and more than 800 unique apple varieties, including an additional analysis of 142 varieties from cider apple germplasms in the United States. The biochemical traits of many varieties exhibited plasticity, and the characterization of a subset of varieties using two cider classification system revealed that most belonged to the “sweet” or “sharp” (acidic) categories rather than “bitter” (high phenolic content). We also compared the classification of a subset of varieties from two US germplasm resources across two seasons and found varieties that have high percent phenolics and/or malic acid experienced greater biochemical plasticity and potential classification change across vintages. Ultimately, this work provides information regarding the variability in apple biochemical traits and also suggests a unique opportunity for producers to market “vintage” quality.

The influence of two yeast strains on fermentation and flavour composition of cider

AbstractTwo commercial dry strains of Saccharomyces cerevisiae and their different inoculum levels were used to carry out cider fermentation to assess their impact on the quality and volatile flavour composition of cider. Analyses indicated that the composition and production of flavour compounds of ciders are generally significantly affected by the strains and inoculation levels. Additionally, the Uvaferm CM strain produced the lowest amount of relative and total flavour compounds compared to Actiflore PM. According to the PCA, differences in volatile components were observed in ciders obtained from both yeasts. While the 1st and 2nd concentrations of Actiflore PM yeast fall to the same region and the others to the different region, the 1st, 2nd and 3rd concentrations of the Uvaferm CM yeast are located in the same region and the others in the different region. It could be said that the Actiflore PM strain synthesizes compounds (such as ethyl alcohol, relative and total esters) that are effective on the quality of cider, the higher amount that Uvaferm CM. The data obtained can be useful for cider producers.

Aroma Profiles of Dry-Hopped Ciders Produced with Citra, Galaxy, and Mosaic Hops

Cider quality and consumer acceptance are greatly influenced by its aroma. With the continued expansion of the craft cider industry, cider producers are employing techniques such as dry hopping to develop unique flavor profiles. Few studies, however, have explored the VOCs of dry-hopped cider. Herein, we monitor the development of VOCs from pressed apple juice, through fermentation and dry hopping by HS–SPME–GC–MS, to elucidate when and how aroma compounds arise in cider production. In all, 89 VOCs were detected, spanning eight classes of organic compounds. Racking events decreased ester concentrations by 10 ± 1%, but resting on the lees allowed these pleasant, fruity aromas to be reestablished. Dry hopping was conducted with three types of hops (Citra, Galaxy, and Mosaic). The varied development of terpenes and esters between hop varieties supports the use of this technique to diversify the aroma profiles of ciders. Herein, we report that both the variety of hops and the timing of key processing steps including racking and hop addition significantly alter the identity and concentration of aroma-important VOCs in dry-hopped cider.

Screening and Identification of Yeasts from Fruits and Their Coculture for Cider Production

Coculturing non-Saccharomyces yeasts with Saccharomyces cerevisiae could enrich the aromatic complexity of alcoholic beverages during cider brewing. Therefore, the present study performed rapid strain screening via selective culture medium and aroma analysis and adopted a response surface methodology to optimize fermentation conditions to produce 2-phenylethyl acetate (PEA), which presents a rose and honey scent. The effects of coculturing yeasts on cider quality were evaluated through hedonic sensory analysis and the check-all-that-apply (CATA) method. Hanseniaspora vineae P5 and S. cerevisiae P1 produced ciders with high levels of PEA and 2-phenylethanol, respectively. The optimal fermentation process consisted of sequential inoculation with a 31 h delay between inoculations, followed by fermentation for 14.5 d at 18.7 °C, yielding 17.41 ± 0.51 mg/L of PEA, which was 4.6-fold higher than that obtained through the unoptimized fermentation process. Additionally, the CATA results revealed that the cider produced through coculturing was associated with descriptors such as “smooth taste”, “honey”, “pineapple”, and “fruity”, which can be attributed to the high ethyl acetate and PEA levels in the cider.

Volatile Profile Survey of Five Apple Varieties Grown in Southwest Colorado from Juice to Finished, Dry-Hopped Cider

The volatile organic compounds (VOCs) produced during cider fermentation, maturation, and dry hopping greatly impact enjoyment of the final product. To investigate the effect of apple variety on VOC development in cider, five apple varieties were picked from two orchards in southwest Colorado. Each apple variety was juiced, fermented with Lalvin QA23 Saccharomyces cerevisiae, dry-hopped with Citra hops, and analyzed separately alongside non-dry hopped controls. The aroma attributes of these historical southwest Colorado apples have never been explored, and few studies have chemically profiled the aromas of dry-hopped cider. A total of 73 VOCs were identified using headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) from fruit juice to cider. Ethyl esters, acetate esters, higher alcohols, and terpenes were the major aroma contributors observed in dry-hopped cider. The identity and concentrations of VOCs varied greatly between apple varieties, with only 24 common VOCs detected in all samples studied. This indicates the importance of apple variety choice in tuning the aroma profile of the finished cider. This method can be used to more effectively evaluate orchard or cider production treatments on cider quality. This case study also provides practical information for cider makers seeking to improve the quality of their products through consideration of fruit variety and dry hopping. Supplemental data for this article is available online at https://doi.org/10.1080/03610470.2021.2013645 .

Bioactive compounds recovered from apple pomace as ingredient in cider processing: monitoring of compounds during fermentation.

The apple pomace-industrial residue of apple beverages manufacture-presents 42-58% of the phenolic content of fresh fruit. As the phenolic composition influences the quality of ciders, it is very relevant to monitor the evolution of these compounds during the industrial process. Therefore, this research aim was to monitor the cider composition with the addition of phenolic extract from apple pomace during the fermentation. Two treatments, S1 (without extract) and S2 (with added extract), were evaluated during 15days of fermentation. After 15 fermentation days, the sample S2 presented an increase of 23% in total phenolic compounds and 40% in flavonoids without harm to the fermentation kinetics. Concerning the evolution of monomeric phenolic compounds, the phenolic acids in S1 and S2 presented a similar trend during the fermentation period. Enzymatic hydrolysis reactions resulted in the chlorogenic acid content decreasing, in line with increased levels of caffeic acid. Phloridzin and quercetin glycosides content showed the greatest increase in S2. The final product S2 presented higher antioxidant activity and some sensorial characteristics (astringency, bitterness and colour) were accentuated. This work shows that phenolic compounds added were maintained during the process and it did not prejudice the fermentation reactions. Therefore, this is a good alternative to valorize apple pomace and improve the functional and sensorial quality of the cider.