Instant Cocoa Research Articles

Desorption electrospray ionization of aerosol particles

We have applied desorption electrospray ionization to aerosol particles. Ions were formed from aerosols by merging suspended dry particles with an electrospray of solvent in a modified ion trap mass spectrometer. Dry aerosol particles were generated using a fluidized bed powder disperser and directed toward the inlet of the mass spectrometer. A nanospray source was used to create a spray of solvent droplets directed at the inlet and at a right angle with respect to the aerosol. Ions generated by the interaction of the particles and electrospray were transferred into the ion trap mass spectrometer. Using this method, pure samples of caffeine and erythromycin A were analyzed. In addition, commonly available food and drug powders including instant cocoa powder, artificial sweetener and ibuprofen were analyzed.

Modulation of perceived taste by olfaction in familiar and unfamiliar beverages

The integration of olfactory and taste perception and the role of congruency and familiarity on perception have already been demonstrated in model solutions. The aim of the present study was to investigate the role of these factors in real food products. Therefore, we have investigated the impact of olfactory perception on perceived bitterness in a familiar (bitter cocoa beverage) and an unfamiliar (bitter milk) beverage. Sensory profilings with and without noseclip were conducted according to simultaneous product presentation. In a first experiment, an instant cocoa powder mixed with water was used to prepare a common base. Two types of flavourings were added: cocoa and vanilla, at three different levels (none, medium and high). Samples were compared within a flavouring type. In a second experiment a vanilla flavour was added at three levels to a milk base containing caffeine. The panellists scored bitterness, sourness, sweetness and body with noseclip. Without noseclip, overall aroma above the cup and in mouth were assessed in addition to the previous set of attributes. With noseclip, results showed that neither the cocoa nor the vanilla flavourings provided any additional taste to the beverages. Without noseclip, olfactory/taste interaction in the cocoa beverage led to an enhancement of bitterness induced by the cocoa flavouring and an increase in sweetness from the vanilla flavouring. On the contrary, in the caffeinated milk, the addition of vanilla flavouring did not significantly increase sweetness, but unexpectedly enhanced bitterness. This study is further evidence of the influence of olfaction on taste perception in complex matrices. In addition, our results suggest that taste–olfaction integration is product dependent and related to food experience, even when working with trained subjects. Furthermore, the unpleasantness due to the neophobia related to the consumption of a new product and to bitterness may enhance bitterness when the unfamiliarity of the product is increased by addition of vanilla flavouring to a bitter milk beverage.

WHEELCHAIR‐MODIFIED SENSORY BOOTHS DO NOT INFLUENCE EVALUATION OF CHOCOLATE PUDDING

ABSTRACTThe objective of this study was to demonstrate that the dimensions of a sensory booth modified to comply with the Americans with Disabilities Act of 1990 (ADA) guidelines have no impact on consumer evaluations of chocolate pudding. One set of booths each were constructed per ASTM and ADA guidelines. Control pudding was prepared according to package directions with 2% fat milk; other treatments were modified with red food coloring, sugar or nonfat milk. Twenty‐four panelists evaluated instant chocolate puddings in directional difference and hedonic tests in each type of booth. Booth type and test date had no effect on judgments.

SENSORY‐RHEOLOGICAL RELATIONSHIPS IN INSTANT HOT COCOA DRINKS

Fourteen samples of instant cocoa drinks with different compositions of main ingredients (cocoa, milk, sugar) and stabilizer content were evaluated by a trained sensory panel. Fifteen sensory attributes concerning appearance, odor, texture and flavor were evaluated with focus on the complex term mouthfeel. The sensory properties of the cocoa drinks were related to measured physical, chemical and rheological properties by means of Partial Least Squares Regression. A high positive covariation was revealed between sensory and rheological measured viscosity properties. Mouthfeel in cocoa drinks was found to depend on both viscosity and flavor properties. These findings suggest that in addition to the prevailing ISO definition of mouthfeel, which is limited to a description of tactile characteristics, interaction with flavor may be included. Both stabilizer and main ingredients were shown to have distinct effects on the sensory properties. A consumer test showed a negative correlation between mouthfeel and consumer preference, within the range of cocoa drinks studied.

Simultaneous and Simple Determination of Saccharin and Acesulfame K in Foods by GC-NPD

A rapid and simple method for the simultaneous determination of saccharin (SA) and acesulfame K (AK) in foods by GC-NPD was developed. A good extraction rate was obtained by using ethyl acetate as an extraction solvent and high sensitivity was obtained by using GC-NPD. Interfering substances were removed or reduced effectively by clean-up using an acidic alumina cartridge column.The detection limit was 5 ppm in samples, and SA and AK were confirmed by GC/MS. The proposed method was applied to 89 samples of imported foods, such as soft drinks, instant cocoa and confectionery.

Evaluation of bitterness and astringency of polyphenolic compounds in cocoa powder

Total polyphenols, tannins, (-)-epicatechin and colorimetric fractions were determined in six samples of three batches of cocoa beans subjected to various stages of fermentation (1-8 days), in 36 samples of non-alkalinized low fat cocoa powder and 15 samples of instant cocoa powder. The physico-chemical data obtained were related to sensory evaluation and submitted to analysis of variance, multivariate distribution (Mahalanobis distance) and Pearson Chi-squared test. From the results obtained, we can infer that optimally fermented cocoa samples have a maximum total polyphenols of 58 mg g-1, a tannins of 31 mg g-1, and a (-)-epicatechin of 3 mg g-1. Correspondence was not found between colorimetric fraction values and sensory data. These parameters are related to the sensory properties of cocoa and can be used to confirm deficiencies. © 1997 Published by Elsevier Science Ltd

Parameters affecting the quality of processed cocoa powder: acidity fraction

Total, free and fixed, volatile and non-volatile acids, as well as lactic and phosphoric acid contents were determined in six samples of three batches of cocoa beans subjected to various stages of fermentation (1–6 days), in 37 samples of non-alkalinized low-fat cocoa powder and in 15 samples of instant cocoa powder. The physico-chemical data obtained were related to sensory evaluation and submitted to analysis of variance, multivariate distribution (Mahalanobis distance) and the Pearson Chi-squared test. From the results obtained we can infer that optimally fermented cocoa samples should have a maximum total fixed acidity of 39 mEq NaOH/100 g, a non-volatile fixed acidity of 35 mEq NaOH/100 g, and a lactic acid content of 0.50 g/100 g (5.5 mEq/100 g). No correlation was found to occur between other acidities, the phosphoric acid content, and sensory data. These parameters are related to the sensory properties of cocoa and can be used to confirm deficiencies.

Claims and errors in food and nutrition advertisements broadcast by two Spanish television channels

This investigation analyses the messages delivered in food/nutrition advertisements broadcast by Spanish TV (n= 489). The study period covered the 6 peak hours of each day during the first week of October 1993. Advertisements were coded for product type and advertising claims. The messages most frequently used to promote the sale of a product were taste (58%), followed by quality (27%), novelty (26%), healthiness (23%), nutritional value (19%) and natural composition (11%). Advertisements promoting cereals, soft bread, dairy products, baby food, instant cocoa, supplements, fats and oils dealt more with nutritional value, vitamin, mineral or fibre content, and with the product's health‐giving qualities or value in aiding growth and performance. Ninety‐four per cent of advertisement presenters/protagonists were slim or very slim. Thirty‐eight per cent of advertisements contained images of foodstuffs not found in the advertised product at all. Generally these were foodstuffs whose consumption is recommended or normally considered healthy by most people. Milk, fruit, bread, greens, juices and vegetables appeared often. The advertisements made an important number of claims with respect to nutrition. In some cases these messages were incorrect and could contribute to the dissemination of distorted or incorrect ideas. These results could help nutrition educators address the problems of misleading advertising and help identify the types of messages received by people when watching television.

Azoreductase activity in bacteria associated with the greening of instant chocolate puddings

Pseudomonas sp. strain AZR1 and Klebsiella sp. strain AZR2 were isolated from reconstituted instant chocolate puddings that had turned green and were found to have azoreductase activity. This activity was inducible and NADH dependent. Differences in dye reduction rates between the two strains were apparent, and substrate specificity related to dye structure was observed.

Microbiological Quality of Cocoa Powder, Dry Instant Chocolate Drink Mix, Dry Nondairy Coffee Creamer and Frozen Nondairy Topping Obtained at Retail Markets

A national survey was conducted of the microbiological quality of three dry ingredients used in beverages and one frozen non-dairy topping obtained at retail markets. Geometric mean aerobic plate counts (APCs) of units examined at 35°C were as follows: 1,313 units of cocoa powder, 6,600 CFU/g; 1,552 units of dry instant chocolate drink mix, 290 CFU/g; 1,559 units of dry non-dairy coffee creamer, 37 CFU/g; and 1,532 units of frozen non-dairy topping, 34 CFU/g. At 30°C, the geometric mean APC was 34 CFU/g for frozen nondairy topping. Geometric means for most probable number determinations of coliform bacteria and Escherichia coli were <3/g for the four products. Geometric mean values for Staphylococcus aureus in three of the products were <10/g; no S. aureus was found in cocoa powder. Geometric mean values for yeasts and molds in dry instant chocolate drink mix and dry nondairy coffee creamer were 8 and 6 CFU/g, respectively.

Application of preparative HPLC in the chemical analysis of food ingredients

Three examples are described for the application of preparative HPLC in food chemistry: isolation of the β-tocopherol fraction from an oily tocopherol mixture, purification of a vitamin D containing extract from instant chocolate powder for further confirmation by mass spectrometry and quantitative determination of vitamin D3, and purification and fraction of an aflatoxin-containing extract from a peanut sample followed by mass spectrometric analysis of the individual fractions containing aflatoxins B1, B2, G1, and G2. The preparation of samples, the preparative and quantitative HPLC chromatograms as well as the chemical ionization mass spectra of the compounds isolated from the extracts by means of preparative HPLC are described.