Cardboard Flavor Research Articles

The use of Oxygen 18 in appraising the impact of oxidation process during beer storage

To appraise the incidence of oxygen: in bottled beer, the stable nonradioactive oxygen isotope 18O(2) was injected into the headspace just before ageing and subsequently analysed by proton bombardment and isotopic mass spectroscopy of all the most interesting beer fractions. Although oxygen did cause considerable oxidation of sulphites, polyphenols, and isohumulones, it was not incorporated into the carbonyl fraction, indicating that the cardboard flavour in beer is not due to lipid oxidation but to wort preparation. Nonenal potential measurement was found to be a good indicator of beer flavour staling. The impact of beer stabilisation treatments (addition of polyvinyl pyrolidone powder, potassium metabisulphite, ascorbic acid) was also investigated.

Investigations of the Protective Mechanism of Sulfite Against Beer Staling and Formation of Adducts with Trans-2-Nonenal

Development of stale cardboard flavor in beer is believed to be associated with liberation or formation of the unsaturated aldehyde trans-2-nonenal, known as an oxidative breakdown product of linoleic acid. During fermentation, brewer's yeast produces sulfite. This naturally produced sulfite— or sulfite added after fermentation—has been shown to contribute to the flavor stability of beer. The present investigation was set up to more closely examine adduct formation between trans-2-nonenal and sodium bisulfite. Three different chemical adducts have been synthesized and characterized by 1H NMR spectroscopy and LC-MS. Formation of adducts in aqueous buffer at beer pH was confirmed indirectly by 1H NMR spectroscopy and directly by LC-MS.

Furanic Aldehyde Analysis by HPLC as a Method to Determine Heat-Induced Flavor Damage to Beer

The temperature at which packaged beer is stored in transit from the brewery to the consumer may profoundly influence the flavor of the product upon consumption. High-temperature storage usually results in accelerated staling and is often accompanied by the development of paper, card-board, and stewed flavor notes. The formation of furanic aldehydes during elevated-temperature storage of many foodstuffs is well documented. This article describes the development of a simple HPLC assay for the detection of furanic aldehydes in beer and the application of this assay to analyze beers which were exposed to high-temperature storage. Furanic aldehydes were found to increase at an approximately linear rate over time, the rate being logarithmically related to the temperature of beer storage. The assay described could be used to detect exposure of beer to elevated temperatures in trade.

Flavor and Oxidative Stability of Roasted High Oleic Acid Peanuts

ABSTRACTA new peanut line has been developed at the University of Florida with about 80% oleic and 3% linoleic acid. Volatiles and sensory characteristics of roasted normal and high oleic acid peanuts stored at 25°C were compared. Volatiles were analyzed using adsorbent trapping and GCMS, a 20‐member trained panel was used for sensory evaluation, and a GC sniffer port was used to evaluate odor characteristics of volatile isolates. Peroxide values were lower for high oleic (HO) peanuts than normal peanuts during storage at 25°C and 40°C. The hexanal content of the peanuts was higher for normal than HO. Peanutty flavor was more stable for HO than normal after 6 wk storage. Painty and cardboard flavors were higher in normal peanuts than HO during storage. Differences for both painty and cardboard flavors were significant after 6 wk storage. Pyrazines were more stable in HO peanuts. Shelf life was estimated from sensory data to be two times longer in HO peanuts.

Physicochemical and Sensory Characteristics of Peanut Paste Stored at Different Temperatures

ABSTRACTWhen peanut paste was stored at 30, 40 and 50°C for up to 1 yr, that held at 30°C for 161 days had minimal deteriorative changes. At 50°C, the primary deterioration was increased browning, oxidized and cardboard flavors, and oil separation. Regression analysis indicated that ratings for chroma, cooked peanut, cardboard, and oxidized flavors were responsible for > 50% of the variation in response. When a detectable oxidized flavor was used as the indicator of storage deterioration, peanut paste had a predicted shelf life of 152 days at 30°C; 98 days at 40°C; and 96 days at 50°C.

Evaluation by multivariate analysis of off-flavor in headspace volatiles formed during storage of beer.

When beers were stored for 0, 1, 2, 3, and 4 weeks at 37°C, a cardboard flavor was generated with the increase in storage terms. Seventy-two peaks detected by GC analysis of headspace gas on beer were used as variables for the multivariate analysis. Nine compounds including furfural and acetoin, which had rotated factor loadings of more than 0.5 on second factor axis, were extracted as components highly correlated with the formation of the cardboard flavor. Furfural and three compounds were extracted as important indices for discrimination of beer with storage terms by stepwise discriminant analysis.

Identifcation of a Compound Responsible for Cardboard Flavor in Beer

Identifcation of a Compound Responsible for Cardboard Flavor in Beer

A Study of the Cardboard Flavour in Beer by Gas Chromatography

(1969). A Study of the Cardboard Flavour in Beer by Gas Chromatography. Proceedings. Annual meeting - American Society of Brewing Chemists: Vol. 27, Proceedings of the Annual Meeting 1969, pp. 123-126.

600. Further observations on the volatile compounds associated with oxidized flavour in skim milk

The C6–C11 2,4–dienals have been identified in distillates from skim milk with oxidized flavour. The C4–C11 2–enals were isolated from the same distillates in a previous investigation. The most abundant individual compounds in the two groups were 2–octenal, 2–nonenal, 2–4–heptadienal and 2,4–nonadienal. These compounds when flavour–tested in skim milk in dilutions of 10–7–10–9 closely resembled oxidized (cardboard) flavour. It is concluded that they are the main constituents of this flavour defect and that they originate from the oxidation of the more highly unsaturated fatty acids in milk lipids.

576. The volatile compounds associated with oxidized flavour in skim milk

Using chromatographic techniques, a number of compounds was isolated from the steam distillates of skim milk containing oxidized (cardboard) flavour. The following compounds were definitely identified: acetone, acetaldehyde, n–hexanal, crotonaldehyde, and the C5 to C11 2-unsaturated aldehydes. Presumptive evidence for the presence of several 2,4-diunsaturated aldehydes of medium chain length was obtained also. Acetaldehyde and acetone were also isolated from normal skim milk; these two compounds appear to play no part in the defect.2-Enals, in particular the C8 and C9, were considered to be the principal flavour-determining compounds. In milk at dilutions of 1 part in 107 to 109 they impart an oxidized type of flavour resembling that known as cardboard. Evidence was obtained that 2,4-dienals were also present and they produced a similar flavour.It may further be deduced that cardboard flavour in milk is caused by the preferential oxidation of di- and polyunsaturated fatty acids.

Separation and Recombination as a Means of Deferring an Oxidized or Cardboard Flavor in Milk during Frozen Storage

Summary The development of an oxidized (cardboard) flavor in milk during frozen storage was deferred by separating the milk, pasteurizing and homogenizing the cream and mixing this cream with the pasteurized skimmilk. Best results were obtained when the temperature of the cream during homogenization was well above the melting point of the fat, the homogenizing pressure exceeded 1,500 lb. per square inch and the fat content of the cream was 25 to 30 per cent. The increased flavor stability of this recombined milk was not sufficient to counteract the catalytic effect of 0.5 ppm. of added Cu. Recombined milk prepared by mixing raw cream and raw skimmilk and then pasteurizing and homogenizing the mixture was more susceptible to the development of an oxidized flavor during frozen storage than the unseparated milk that was similarly pasteurized and homogenized. The difference in susceptibility to the development of an oxidized flavor of the recombined milks prepared by these two methods was not due to a difference in content of lecithin and related substances because the milk was subjected to the same centrifugal forces during separation. Low pressure homogenization of recombined milk made by mixing pasteurized and homogenized 25 to 30 per cent cream and pasteurized skimmilk, increased the susceptibility of the milk to the development of an oxidized flavor. As the pressure was increased the flavor stability of the milk increased until at 2,000 to 2,500 1b. it was no more likely to develop an oxidized flavor than was the same recombined milk before it was homogenized. At the same time, the body stability decreased and there was less tendency to form a cream plug.