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Schlüter A, André A, Hühn T, Rohn S, Chetschik I. Influence of Aerobic and Anaerobic Moist Incubation on Selected Nonvolatile Constituents─Comparison to Traditionally Fermented Cocoa Beans. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:16335-16346. [PMID: 36524976 DOI: 10.1021/acs.jafc.2c06493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Recently, moist incubation has been proposed as an alternative postharvest processing method for cocoa beans. During this treatment, unfermented and dried cocoa nibs are rehydrated with a lactic acid solution containing ethanol and subsequently incubated for 72 h at 45 °C before drying. Previous studies focused on the aroma formation during this treatment and the further processing of chocolate. The current study focused on the influence of aerobic and anaerobic moist incubation on selected nonvolatile components in comparison with the unfermented raw material and traditionally fermented cocoa. Total phenolic content and total flavan-3-ol content, contents of (+)-catechin, (-)-epicatechin, procyanidins B2 and C1, cinnamtannin A2, methylxanthines (theobromine and caffeine), contents of sugars (sucrose, d-glucose, and d-fructose) and free amino acids (17 proteinogenic amino acids) were determined. The fermentation index was also evaluated. The aerobically incubated and fermented cocoa showed low levels of phenolic compounds in comparison to the unfermented cocoa and the anaerobically incubated cocoa. The level of methylxanthines was unaffected by all treatments. The contents of reducing sugars were more than 2-fold higher after both incubation treatments compared to fermentation. The level of free amino acids liberated was highest after anaerobic incubation followed by fermentation and aerobic incubation. The aerobically incubated cocoa showed the highest FI, while the anaerobically incubated cocoa may be considered under-fermented (FI <1.0). Statistical analysis (ANOVA) showed significant differences between all treatments, which was verified by principal component analysis.
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Affiliation(s)
- Ansgar Schlüter
- School of Life Sciences and Facility Management, Institute of Food and Beverage Innovation, Research Group Food Chemistry, ZHAW Zurich University of Applied Sciences, 8820 Wädenswil, Switzerland
- University of Hamburg, Hamburg School of Food Science, Institute of Food Chemistry, 20146 Hamburg, Germany
| | - Amandine André
- School of Life Sciences and Facility Management, Institute of Food and Beverage Innovation, Research Group Food Chemistry, ZHAW Zurich University of Applied Sciences, 8820 Wädenswil, Switzerland
| | - Tilo Hühn
- School of Life Sciences and Facility Management, Institute of Food and Beverage Innovation, Research Group Food Chemistry, ZHAW Zurich University of Applied Sciences, 8820 Wädenswil, Switzerland
| | - Sascha Rohn
- University of Hamburg, Hamburg School of Food Science, Institute of Food Chemistry, 20146 Hamburg, Germany
- Institute of Food Technology and Chemistry, Technische Universität Berlin, 13355 Berlin, Germany
| | - Irene Chetschik
- School of Life Sciences and Facility Management, Institute of Food and Beverage Innovation, Research Group Food Chemistry, ZHAW Zurich University of Applied Sciences, 8820 Wädenswil, Switzerland
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Schlüter A, Hühn T, Kneubühl M, Chatelain K, Rohn S, Chetschik I. Comparison of the Aroma Composition and Sensory Properties of Dark Chocolates Made with Moist Incubated and Fermented Cocoa Beans. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:4057-4065. [PMID: 35316045 DOI: 10.1021/acs.jafc.1c08238] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In a previous investigation, "moist incubation" was described as a novel postharvest treatment for cocoa and the aroma composition of the resulting cocoa nibs was compared to unfermented and fermented cocoa nibs. For this treatment, unfermented and dried nibs are rehydrated with an aqueous solution containing lactic acid and ethanol to adjust the pH value and are subsequently incubated at 45 °C under aerobic conditions for 72 h before drying. The aim of the present study was to investigate the sensory properties and aroma composition of dark chocolates made of these materials after roasting. Therefore, gas chromatography-olfactometry (GC-O) in combination with aroma extract dilution analysis (AEDA), quantitation with isotopically labeled standards, odor activity value (OAV) determination, and sensory analysis were performed. The three different chocolates had distinct sensory and OAV profiles. The sensory profiles showed a higher intensity of fruity aroma notes and a lower intensity of bitterness and astringency in the chocolate made with the moist incubated cocoa, while the chocolate made of fermented cocoa reached higher scores in the roasty aroma notes. Furthermore, higher OAVs were determined for the Strecker aldehydes in the chocolate made of the moist incubated cocoa, whereas higher OAVs for the pyrazines and the acids were detected in the chocolate made of fermented cocoa. In contrast, the chocolate produced with the unfermented cocoa showed low cocoa specific aroma notes and high levels of astringency and bitterness. The detected differences reveal interesting insights into the influence of different postharvest treatments on the resulting aroma composition in the final chocolate. Furthermore, the alternative postharvest treatment was demonstrated to result in chocolates with a pleasant sensory profile.
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Affiliation(s)
- Ansgar Schlüter
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), Wädenswil, 8820 Wädenswil, Switzerland
- Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg, 20146 Hamburg, Germany
| | - Tilo Hühn
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), Wädenswil, 8820 Wädenswil, Switzerland
| | - Markus Kneubühl
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), Wädenswil, 8820 Wädenswil, Switzerland
| | - Karin Chatelain
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), Wädenswil, 8820 Wädenswil, Switzerland
| | - Sascha Rohn
- Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg, 20146 Hamburg, Germany
- Institute of Food Technology and Chemistry, Technische Universität Berlin, 13355 Berlin, Germany
| | - Irene Chetschik
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), Wädenswil, 8820 Wädenswil, Switzerland
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Schlüter A, Hühn T, Kneubühl M, Chatelain K, Rohn S, Chetschik I. Novel Time- and Location-Independent Postharvest Treatment of Cocoa Beans: Investigations on the Aroma Formation during "Moist Incubation" of Unfermented and Dried Cocoa Nibs and Comparison to Traditional Fermentation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:10336-10344. [PMID: 31885268 DOI: 10.1021/acs.jafc.9b06119] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The aroma properties of cocoa nibs obtained by applying a novel postharvest treatment were investigated using methods of the molecular sensory science approach, i.e., solvent extraction and solvent-assisted flavor evaporation, aroma extract dilution analysis (AEDA), stable isotope dilution analysis, calculation of odor activity values (OAVs), and orthonasal sensory evaluation; those properties were then compared to the unfermented and dried raw material and a traditionally fermented sample of the same harvest. For the treatment, unfermented and dried cocoa nibs were, first, rehydrated with lactic acid and ethanol solution to adjust the pH value to 5.1 and, second, incubated under aerobic conditions for 72 h at 45 °C and subsequently dried. This treatment was used to induce enzymatic reactions within the cotyledon matrix, which also occur inside the bean during microbial fermentation of the surrounding fruit pulp. The results of the AEDA showed that many of the key aroma compounds found in fermented and dried cocoa increased during the incubation treatment. Especially some "fruity" esters were found with an equal or even higher flavor dilution (FD) factor in the incubated sample compared to the fermented sample, whereas the fermented sample showed high FD factors for "pungent, sour" and "sweaty" acids, such as acetic acid and 2- and 3-methylbutanoic acids. The quantitative data and calculated OAVs for the samples supported the findings of the AEDA, underlining the potential of this approach as a controllable and reproducible alternative postharvest treatment.
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Affiliation(s)
- Ansgar Schlüter
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), 8820 Wädenswil, Switzerland
| | - Tilo Hühn
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), 8820 Wädenswil, Switzerland
| | - Markus Kneubühl
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), 8820 Wädenswil, Switzerland
| | - Karin Chatelain
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), 8820 Wädenswil, Switzerland
| | - Sascha Rohn
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), 8820 Wädenswil, Switzerland
| | - Irene Chetschik
- Life Sciences and Facility Management, Zurich University of Applied Sciences (ZHAW), 8820 Wädenswil, Switzerland
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Jinap S, Ikrawan Y, Bakar J, Saari N, Lioe H. Aroma Precursors and Methylpyrazines in Underfermented Cocoa Beans Induced by Endogenous Carboxypeptidase. J Food Sci 2008; 73:H141-7. [DOI: 10.1111/j.1750-3841.2008.00858.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Bittner S. When quinones meet amino acids: chemical, physical and biological consequences. Amino Acids 2006; 30:205-24. [PMID: 16601927 DOI: 10.1007/s00726-005-0298-2] [Citation(s) in RCA: 227] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2005] [Accepted: 10/24/2005] [Indexed: 10/24/2022]
Abstract
Quinones and amino acids are usually compartmentally separated in living systems, however there are several junctions in which they meet, react and influence. It occurs mainly in wounded, cut or crushed plant material during harvest, ensiling or disintegrating cells. Diffusing polyphenols are oxidized by polyphenol oxidases (PPOs) to quinonic compounds, which associate reversibly or irreversibly with amino acids and proteins. The reaction takes place with the free nucleophilic functional groups such as sulfhydryl, amine, amide, indole and imidazole substituents. It results in imine formation, in 1,4-Michael addition via nitrogen or sulphur and in Strecker degradation forming aldehydes. The formation and activity of quinone-amino acids conjugates influences the colour, taste, and aroma of foods. Physical and physiological phenomena such as browning of foods, discoloration of plants during processing, alteration of solubility and digestibility, formation of humic substances, germicidal activity, cytotoxicity and more occur when quinones from disintegrating cells meet amino acids. The mechanisms of toxicity and the pathways by which PCBs may be activated and act as a cancer initiator include oxidation to the corresponding quinones and reaction with amino acids or peptides. Sclerotization of insect cuticle is a biochemical process involving also the reaction between quinones and amino acid derivatives.
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Affiliation(s)
- S Bittner
- Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva, Israel.
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Kirchhoff PM, Biehl B, Crone G. Peculiarity of the accumulation of free amino acids during cocoa fermentation. Food Chem 1989. [DOI: 10.1016/0308-8146(89)90071-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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7
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Biehl B. Ver�nderungen der subcellul�ren Struktur in Keimbl�ttern von Kakaosamen (Theobroma cacao L.) w�hrend der Fermentation und Troeknung. ACTA ACUST UNITED AC 1973. [DOI: 10.1007/bf01080112] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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8
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CO H, SANDERSON GW. BIOCHEMISTRY OF TEA FERMENTATION: CONVERSION OF AMINO ACIDS TO BLACK TEA AROMA CONSTITUENTS. J Food Sci 1970. [DOI: 10.1111/j.1365-2621.1970.tb12128.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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