Cider Production Research Articles

Volatile organic compounds from Starmerella bacillaris to control gray mold on apples and modulate cider aroma profile

Gray mold caused by Botrytis cinerea is a fungal disease that can determine significant economic losses of apple during the storage phase. An alternative to reduce the use of traditional synthetic fungicides is to employ the yeast Starmerella bacillaris as biological control agent (BCA), also with positive effect on apple juice fermentation for the production of cider. Thus, we aimed to evaluate the safety of 16 S. bacillaris strains and their ability to control B. cinerea. In addition, the fermentation performances in apple juice and the volatile organic compounds (VOCs) profile were assessed, both in single-strain and in sequential fermentations with Saccharomyces cerevisiae. The in vitro assays showed that all S. bacillaris strains can be considered safe from the analyzed virulence factors, and were able to significantly constrain the growth of B. cinerea, reducing mycelial growth of 50% in dual-culture and of 90% through VOCs. Moreover, in vivo antagonistic assays revealed a visible decrease of gray mold rot symptoms on apples confirming the potential of S. bacillaris as BCA. GC-MS analysis of the ciders obtained showed increased concentrations in the sequential fermentation of some higher alcohols and terpenes, positively correlated with the cider aromatic quality, and suggested the involvement of benzyl alcohol, known for its antimicrobial action, in the biocontrol efficacy.

Various factors affect product properties in apple cider production

Different parameters in cider processing were evaluated using different cultivars of Norwegian-grown table apples measuring the quality of cider. Seven different apple cultivars were mixed into four different apple juice mixtures. In this experiment, we evaluated the maturation of the apples along with commercial cider yeast and spontaneous alcoholic fermentation. Other parameters were fermentation temperature and filtration along with content of polyphenols, organic acids and volatile compounds that was analysed as an effect of the fermentation process. Succinic acid was the major organic acid in apples and ciders. The different apple juice mixtures did not reveal pyruvic and acetic acids but they appeared in relatively high amount in the ciders. The level of citric acid increased from apple to cider. Chlorogenic acid was the major polyphenolic compound found from 13-109 mg L-1 in the apple juice mixtures and between 27-200 mg L-1 in the ciders. The higher alcohol 3-methyl-1-butanol appeared in relatively large amounts in all the ciders (91-166 mg L-1). The average content of acetaldehyde increased during the fermentation process, from apple juice mixtures 2.75 mg L-1 and 14.65 mg L-1 in the ciders. The content also increased for ethyl acetate with levels at 0.1 mg L-1 in the apple juice mixture and 20 mg L-1 in the cider. In the sensory evaluation experiment, the ciders produced from the apple cultivars Aroma, Gravenstein and Summerred got higher scores in fruitiness and complexity compared to the other apple juice mixtures.

Predictive Models for Optimisation of Acetone Mediated Extraction of Polyphenolic Compounds from By-Product of Cider Production

Response surface methodology (RSM) was applied to provide predictive models for optimisation of extraction of selected polyphenolic compounds from cider apple pomace under aqueous acetone. The design of experiment (DoE) was conducted to evaluate the influence of acetone concentration % (v/v), solid-to solvent ratio % (w/v), temperature (&#730C) and extraction time (min) and their interaction on phenolic contents, using the Central Composite Rotatable Design (CCRD). The experimental data were analysed to fit statistical models for recovery of phenolic compounds. The selected models were significant (P 0.05), except for Chlorogenic acid and Quercetin 3-glucoside which had significant lack of fits (P R2 > 0.9000 and adjusted reasonable agrees with predicted . Coefficient of variation < 5% for each determination at the 95% confidence interval. These models could be relied upon to achieve optimal concentrations of polyphenolic compounds for applications in nutraceutical, pharmaceutical and cosmetic industries.

Ultrasound-assisted fermentation for cider production from Lebanese apples.

The present work studies the impact of low-intensity ultrasound (US) on Hanseniaspora sp. yeast fermentations. The effect of pulse duration and growth phase on US application was first evaluated using a synthetic medium. The optimal conditions were then applied to apple juice US-assisted fermentation. An US treatment chamber was first designed to allow the recycling of the culture medium. The optimal US pulse duration on the yeast growth rate was of 0.5s followed by 6s rest period, and during 6h of both Lag and Log phases. These US parameters led to a faster consumption of glucose in the medium during the fermentation, compared to the untreated culture. The impact of US was also depending on the growth phase, showing higher sensitivity of the yeast to US during the Lag phase rather than the Log phase. US-assisted fermentation of apple juice showed a significant increase in biomass growth and glucose consumption, along with a significant decrease in the ethanol yield. The fastest growth kinetic (by 52%), and the highest ethanol reduction (by 0.55% (v, v)) were obtained for the treatment during the first 12h of fermentation, thereby, the stationary phase was reached faster, and the maximum biomass growth rate was 10 folds higher compared to the untreated culture. The results obtained in this study demonstrated the promising efficiency of US-assisted fermentation in stimulating the biomass growth and reducing the ethanol content in alcoholic beverages.

Assessment of chemical composition and sensorial properties of ciders fermented with different non-Saccharomyces yeasts in pure and mixed fermentations

This work presents the attempt to enhance the flavor complexity of cider fermented by different non-Saccharomyces species. Pichia kluyveri and Hanseniaspora vineae pure cultures were used as reference ciders. Mixed cultures between all 4 species gave 5 fermentations, where Hanseniaspora uvarum or Torulaspora quercuum were included for apple juice fermentation. Chemical composition and sensorial properties of all ciders were studied. The results indicated that the growth of P. kluyveri and H. vineae were interreacted and also affected by H. uvarum and T. quercuum. H. vineae was more capable of consuming sugar than P. kluyveri. Ciders from the single culture fermentation with P. kluyveri (Pk), as well as from mixed fermentation with P. kluyveri and H. uvarum (Pk-Hu), had high residual sugar, sugar/acid ratio, and glucose-fructose consumption ratio. Large shifts in the consumption and production of organic acids and polyphenols among all ciders were observed. The calculation of the relative odor activity value (rOAV) showed that 17 volatile compounds had an rOAV >1 in at least one sample, and acetate esters and ethyl esters were the groups with the highest number of volatile compounds of importance to the cider aroma. Among these 17 compounds, 3-methylbutyl acetate, 2-methylbutyl acetate, ethyl hexanoate, ethyl octanoate, and β-damascenone exhibited high rOAVs in some ciders and might contribute fruity, floral, and sweet features to the cider aroma. Besides, the tropical fruity aroma from 3-methylbutyl acetate was only perceived in Pk and Pk-Hu. The partial least squares regression (PLSR) analysis revealed that acetate esters contributed positively to the roasted and cooked odor of all ciders. This is the first study evaluating simultaneous fermentation of two non-Saccharomyces yeasts to produce cider, which provides new insights into cider production.

NMR-based metabolic profiling of different yeast fermented apple juices

NMR based metabolic profiling was used to investigate metabolic changes in ciders fermented by yeast species as valuable tool for the identification of metabolites responsible for yeast activities. 1H NMR spectra of apple ciders produced by Saccharomyces cerevisiae EC1118, Torulaspora delbrueckii TD291, Starmerella bacillaris YR21, Hanseniaspora osmophila HO16, Hanseniaspora uvarum Y4M, and Saccharomyces uvarum SU3, revealed to be dominated by glycerol and organic acids signals. The aromatic region showed the presence of low intense signals referred to epicatechin, catechin, chlorogenate, xanthine, uracil, tyrosol, fumarate, histamine, and histidine. The anomeric region showed signals related to xylose, arabinose, glucose, fructose and sucrose. Finally, in the aliphatic region, signals due to amino acids like alanine, aspartate, asparagine, isoleucine and threonine, organic acids like acetate, lactate, malate, pyruvate, quinate, succinate, and alcohols like 2,3 butanediol, ethanol, and glycerol and sterol were detected. Principal component analysis performed considering NMR data from either all spectral regions and only aromatic region revealed the potentiality to discriminate the yeast action. Signals due to glucose, fructose, glycerol, malate, fumarate, tyrosol, histidine, and histamine resulted discriminant for sample differentiation. This study, the first one by NMR, provides preliminary insights on the metabolic differences among yeast species involved in cider production.

The Long Ashton Legacy: Characterising United Kingdom West Country cider apples using a genotyping by targeted sequencing approach

Societal Impact StatementThe English West Country is the home of cider making, providing the region with jobs and industry, as well as cultural reference points such as Laurie Lee's Cider with Rosie. Many important cider apple varieties were developed at Long Ashton Research Station (LARS), near Bristol, UK, including 29 varieties known collectively as ‘The Girls’. After its closure, some of the knowledge and expertise acquired at Long Ashton was lost, including the pedigree of ‘The Girls’. We sampled LARS’ derived trees and, using a novel genotyping technique, rediscovered the pedigree of ‘The Girls’, ensuring that this important cider apple collection will be available for future generations. Summary Our research had two objectives: (a) record the influence of Long Ashton Research Station on the introduction of new cider apple cultivars to the UK; (b) rediscover the parentage of the cider apple cultivars known collectively as ‘The Girls’. For rapid, cost effective and accurate genotyping, we used the recently developed, medium density, single nucleotide polymorphism‐based genotyping procedure, SEQSNP®, to characterize the cultivars. We generated a medium density (1,500 markers), whole genome genotype for 245 apple cultivars that allowed us to determine the relationship between cultivars and, in so doing, rediscover the parentage of ‘The Girls’. We show that SNP genotyping is an efficient tool for the analysis of genetic diversity in cider apples and apples in general, and that the cider apple breeding programme carried out at Long Ashton Research Station made, and continues to make, a unique contribution to UK cider production.

Chemical composition, sensorial properties, and aroma-active compounds of ciders fermented with Hanseniaspora osmophila and Torulaspora quercuum in co- and sequential fermentations

In this study, apple juice was fermented using Hanseniaspora osmophila X25-5 in pure culture as well as mixed culture with Torulaspora quercuum X24-4, which was inoculated simultaneously or sequentially. H. osmophila inhibited the growth of T. quercuum, while T. quercuum had little effect on the growth of H. osmophila. The simultaneous fermentation consumed relatively more sugar and resulted in the highest ethanol content. The production of organic acids varied depending on the yeast species employed and inoculation modality. Esters and alcohols were the main volatile families produced during fermentation, while ethyl esters and terpenes contributed most to the temperate fruity aroma. Gas chromatography-olfactometry (GC–O) showed that 3-methyl-1-butanol, ethyl 2-methylbutanoate, phenylethyl alcohol, β-phenethyl acetate, and β-damascenone were the most potent odorants in all samples. This study suggested that simultaneous fermentation with H. osmophila and T. quercuum might represent a novel strategy for the future production of cider.

An HS-SPME-GC-MS Method for Profiling Volatile Compounds as Related to Technology Used in Cider Production.

Volatile aromatic compounds have a major impact on the final organoleptic properties of cider, and their profiles are influenced by a number of parameters that are closely related to production technologies, especially with regard to the raw material, the microorganism used and the fermentation process. In this work, the profiles of volatile compounds (4 fatty acids, 6 higher alcohols and 12 esters) from 34 European ciders were studied using HS-SPME-GC-MS. Volatiles were isolated by HS-SPME using a CAR/PDMS fiber. Analytical data were statistically evaluated using principal component analysis, and differences in composition of volatiles between cider produced using “intensified” technologies and that of ciders produced by traditional production processes were demonstrated. This difference was mainly due to varying contents of some higher alcohols (2-methylpropanol, isoamyl alcohols, hexanol, and butane-2,3-diol) and esters (ethyl 2-methylbutanoate, butylacetate, and hexyl acetate).

Side Appel Amenability to Ontario

My thesis research involves an evaluation of apple production for the rapidly expanding Ontario cider industry. This entails several experiments that provide an analysis of several apple cultivars. These include apples from traditional global cider regions, established Ontario varieties, and novel crab-derived varieties. Firstly, a report on the cider-centric sensory characteristics of these apples will be published. Additionally, the winter hardiness of varieties with historic use in cider making will be established using microscopy methods. This will provide a minimum cultivation temperature for use in planting decisions throughout Ontario’s apple growing regions. A major concern of Ontario apple grower’s is the cost of harvest labour. For this purpose, I am evaluating the economics of mechanical harvesting in high-density orchards. Lastly, I am exploring the suitability of ice cider production in Ontario to provide methodology recommendations. My project seeks to support the expanding Ontario cider industry through providing localized guidelines.

Genome sequence and characterization of the bcs clusters for the production of nanocellulose from the low pH resistant strain Komagataeibacter medellinensis ID13488.

Summary Komagataeibacter medellinensis ID13488 (formerly Gluconacetobacter medellinensis ID13488) is able to produce crystalline bacterial cellulose (BC) under high acidic growth conditions. These abilities make this strain desirable for industrial BC production from acidic residues (e.g. wastes generated from cider production). To explore the molecular bases of the BC biosynthesis in this bacterium, the genome has been sequenced revealing a sequence of 3.4 Mb containing three putative plasmids of 38.1 kb (pKM01), 4.3 kb (pKM02) and 3.3 Kb (pKM03). Genome comparison analyses of K. medellinensis ID13488 with other cellulose‐producing related strains resulted in the identification of the bcs genes involved in the cellulose biosynthesis. Genes arrangement and composition of four bcs clusters (bcs1, bcs2, bcs3 and bcs4) was studied by RT‐PCR, and their organization in four operons transcribed as four independent polycistronic mRNAs was determined. qRT‐PCR experiments demonstrated that mostly bcs1 and bcs4 are expressed under BC production conditions, suggesting that these operons direct the synthesis of BC. Genomic differences with the close related strain K. medellinensis NBRC 3288 unable to produce BC were also described and discussed.

Management of Apple Maturity and Postharvest Storage Conditions to Increase Polyphenols in Cider

Hard cider production in the United States has increased dramatically during the past decade, but there is little information on how harvest and postharvest practices affect the chemistry of the resulting cider, including concentrations of organoleptically important flavanols. For 2 years we assessed fruit, juice, and cider from a total of five apple (Malus ×domestica Borkh.) cultivars in two experiments: sequential harvests and postharvest storage. Different cultivars were used in 2015 and 2016 with the exception of ‘Dabinett’, which was assessed in both years. There were no differences in polyphenol concentrations in cider made from fruit that was harvested on three separate occasions over a 4-week period in either 2015 or 2016. Fruit storage durations and temperatures had little influence on the chemistry when the experiment was conducted in 2015, but polyphenol concentration was greater after storage in the 2016 experiment. In 2016, total polyphenols in ‘Dabinett’ ciders were 51% greater after short-term storage at 10 °C and 67% greater after long-term storage at 1 °C than the control, which was not subjected to a storage treatment. In 2016, total polyphenols in ‘Binet Rouge’ ciders were 67% greater after short-term storage at 10 °C and 94% greater after long-term storage at 1 °C than the control. Although results varied among cultivars and harvest years, storing apples for longer periods of time and at warmer temperatures may be a strategy to increase polyphenol, particularly flavanol, concentrations in hard cider.

Food Safety Modernization Act Produce Safety Rule Compliance for United States Hard Cider Producers Using Ground-harvested Apples

Apples (Malus domestica) are considered covered, or “nonexcluded,” produce under the Food Safety Modernization Act Produce Safety Rule. The rule states that fruit that has unintentionally come in contact with the ground may not be used for human consumption unless there have been sufficient processing steps to reduce the risk of human pathogens in the final food product. Cider apples destined for hard cider production in many regions have traditionally been harvested at full ripeness when the fruit naturally drops or is easily shaken off the tree. This work reviews the status of cider apples under the Produce Safety Rule, presents the human pathogens of concern with usage of ground-harvested fruit, and describes recommendations, including processing steps, for cider apple growers and cider producers so they can ensure that their product is safe and that they are complying with the rule.

Multiplex PCR for rapid identification of major lactic acid bacteria genera in cider and other fermented foods

Lactobacillus, Pediococcus, Oenococcus and Leuconostoc are the main Lactic Acid Bacteria (LAB) genera present in cider as they are able to survive this hostile environment. LAB play a significant role in cider quality, for example in the process of malolactic fermentation, even though they can also be involved in spoilage of cider (production of biogenic amines, exopolysaccharides, off-flavours…). In this context a better monitoring of the fermentation process is a matter of interest to guarantee cider quality. In the present study, we designed a genus-specific multiplex PCR for a rapid and simultaneous detection of the four main LAB genera involved in cider production. This multiplex PCR worked equally with purified genomic DNA of bacterial isolates and with colonies directly picked from agar plates. This new PCR method was also successfully extended to wine and dairy isolates, and thus constitutes an effective tool to quickly identify LAB associated with fermented foods. Moreover, many biodiversity studies would also benefit from this fast, cheap and reliable identification method.

Juice Clarification with Pectinase Reduces Yeast Assimilable Nitrogen in Apple Juice without Affecting the Polyphenol Composition in Cider.

The term "cider" refers to the fermented beverage produced from apples. The rapid growth in the cider industry coupled with the prominence of traditional, or craft, approaches emphasizes the need for research on cider production. A common problem in ciders is the production of sulfur off-aromas by yeast during fermentation. Prefermentation juice clarification has the potential to reduce the occurrence of unwanted sulfur off-aromas. Concerns that prefermentation juice clarification will reduce the yeast assimilable nitrogen (YAN) and polyphenols in the juice have limited the application of this practice by cider makers. In this study, 3 clarification methods were applied to 'York' apple juice, that is, static settling, centrifugation, and pectinase. Raw (control) and clarified juice were fermented to cider, and the impact of clarification on the physicochemical parameters, amino acids and polyphenol content of the juice and cider was assessed. Juice clarification by pectinase decreased YAN by 50%, while static settling and centrifugation increased the concentration of most amino acids by 83%. All clarification treatments lowered the concentration of total polyphenols in the juice (from 60% to 30%, P < 0.05) and affected the individual polyphenols in the juice but these changes were not evident in the ciders. These findings demonstrate that prefermentation juice clarification results in changes in the chemistry profiles of apple juice. These changes were however not evident in the ciders. This approach therefore has the potential to limit the production of sulfur off-aromas during cider production without adverse effects on quality. PRACTICAL APPLICATION: Clarification of apple juice changes polyphenol and nitrogen contents, factors known to affect cider quality. However, these differences in the chemical profile of apple juice may not be reflected in the finished ciders. These findings demonstrate that juice clarification can be employed in cider making without affecting the quality. Cider makers should not assume that changes in apple juice imparted by clarification will be reflected in the finished ciders. Outcomes should be measured in finished ciders, rather than juice to accurately evaluate effects of the processing steps on quality.

Constraint guided accelerated search for mixed blocking permutation flowshop scheduling

Mixed Blocking Permutation Flowshop Scheduling Problem (MBPFSP) with the objective of makespan minimisation is NP-Hard. It has important industrial applications that include the cider production industry. MBPFSP has made some progress in recent years. However, within practical time limits, existing incomplete algorithms still either find low quality solutions or struggle with large problems. One key reason behind this is the typical way of using generic heuristics or metaheuristics that usually lack problem specific structural knowledge. In MBPFSP, a machine could be blocked with the currently finished job until the subsequent machine is available to process the same job. These blocking constraints affect the makespan. So MBPFSP search should naturally take explicit steps to take the blocking constraints into account. Unfortunately, existing research on MBPFSP just uses only the makespan to compare generated solutions, but the search otherwise is not aware of the blocking constraints. Moreover, existing such methods use either an exhaustive or a random neighbourhood generation strategy. In this work, we aim to advance MBPFSP search by better exploiting the problem specific structural knowledge. We use the constraint and the objective functions to obtain such problem specific knowledge and we exploit such knowledge both in a constructive search method and in a local search method. In this paper, we also present an acceleration method to efficiently evaluate insertion-based neighbourhoods of MBPFSP. Our experimental results on three standard testbeds demonstrate that our proposed algorithms significantly improve over existing best-performing algorithms.

Assessment of yeasts for apple juice fermentation and production of cider volatile compounds

At present, yeasts suitable for apple juice fermentation to produce cider have received scarce attention with respect to wine yeasts. In this study, Saccharomyces and non-Saccharomyces strains were investigated for their capacity to ferment apple juice and to influence the volatile compound production in cider. In a first fermentation trial, seven out of 18 yeasts, belonging to Saccharomyces cerevisiae, S. uvarum, Torulaspora delbrueckii, Hanseniaspora osmophila, H. uvarum, Starmerella bacillaris and Zygosaccharomyces bailii, were selected according to their fermentative performance. The effects of these strains on the volatile composition of cider, produced in a second apple fermentation trial, were then evaluated. Significant differences on the production of alcohols, esters and fatty acids were observed. Large amounts of 2-phenylethanol were found in S. uvarum cider. Hanseniaspora uvarum was the greatest producer of hexyl and isoamyl acetate among non-Saccharomyces yeasts. Ciders were well discriminated by principal component analysis. This study provides insights into the actual capacity to produce volatile compounds that the different yeast species that could be used in single or mixed apple juice fermentation for cider production.

Local Search for Flowshops with Setup Times and Blocking Constraints

Permutation flowshop scheduling problem (PFSP) is a classical combinatorial optimisation problem. There exist variants of PFSP to capture different realistic scenarios, but significant modelling gaps still remain with respect to real-world industrial applications such as the cider production line. In this paper, we propose a new PFSP variant that adequately models both overlapable sequence-dependent setup times (SDST) and mixed blocking constraints. We propose a computational model for makespan minimisation of the new PFSP variant and show that the time complexity is NP Hard. We then develop a constraint-guided local search algorithm that uses a new intensifying restart technique along with variable neighbourhood descent and greedy selection. The experimental study indicates that the proposed algorithm, on a set of wellknown benchmark instances, significantly outperforms the state-of-the-art search algorithms for PFSP.

Waste mitigation: From an effluent of apple juice concentrate industry to a valuable ingredient for food and feed applications

Retentate is a by-product of the concentrate apple juice industry, resultant from clarification through an ultrafiltration process. It has a liquid to sludgy appearance, with 8% of total solids content, usually discarded as industrial waste, conveyed as wastewater directly to the sewage plant. However, its origin and expected composition may allow to define its use as a source of valuable compounds as well as its application in food and feed. The present work shows that retentate is very rich in carbohydrates, namely 40% fructose (dry weight), glucose (8%), oligosaccharides (5%), and polysaccharides (3%). It is also rich in protein (8%) and an available and inexpensive source of β-sitosterol (0.6%). This was the major sterol identified, accounting for 21% of total lipophilic compounds recovered by n-hexane. The retentate suspension was successfully used as nutritive medium for production of cider by a microbrewery and the protein-rich water insoluble material (28% of protein) was successfully used in feed formulations for racing pigeons.

Yeast species diversity in apple juice for cider production evidenced by culture-based method.

Identification of yeasts isolated from apple juices of two cider houses (one located in a plain area and one in an alpine area) was carried out by culture-based method. Wallerstein Laboratory Nutrient Agar was used as medium for isolation and preliminary yeasts identification. A total of 20 species of yeasts belonging to ten different genera were identified using both BLAST algorithm for pairwise sequence comparison and phylogenetic approaches. A wide variety of non-Saccharomyces species was found. Interestingly, Candida railenensis, Candida cylindracea, Hanseniaspora meyeri, Hanseniaspora pseudoguilliermondii, and Metschnikowia sinensis were recovered for the first time in the yeast community of an apple environment. Phylogenetic analysis revealed a better resolution in identifying Metschnikowia and Moesziomyces isolates than comparative analysis using the GenBank or YeastIP gene databases. This study provides important data on yeast microbiota of apple juice and evidenced differences between two geographical cider production areas in terms of species composition.