Honey in Non-Alcoholic Juice Beverages

Summary of a research project funded by the National Honey Board and conducted at the University of Nebraska-Lincoln. Investigator: M.B. Preston

Background

Ergogenic, organic, “all-natural”, nutraceutical–these buzzwords often bring success to products whose labels display them. In this age of ever-growing awareness of functional, natural foods, both honey and herbs are favorites among consumers interested in health. Teas, herbal drinks, fruit-based drinks and sodas sweetened with honey are growing in popularity. In these non-alcoholic beverages, honey serves as a carbohydrate/high energy source and provides flavor, sweetness, color and mouthfeel. However, the market for combining honey with botanical ingredients remains relatively untapped.

Objectives

The goal of this project was to develop two fruit juice beverages containing honey
and botanicals. Juice beverages containing ginseng or chamomile and sweetened with honey would have great appeal to today’s consumers. The two main objectives of this project were 1) to formulate two different types of non-alcoholic beverages utilizing honey as the sole sweetener source and 2) to
characterize the effects of the addition of liquid clover honey on non-alcoholic juice beverages. Specific objectives were as follows:

To formulate two nonalcoholic beverages: a cranberry juice-based beverage and a lemon juice-based beverage each containing a botanical ingredient
To determine the effect of honey on bitterness and acidity in juice beverages over time
To determine the effect of honey on the modification or intensification of desirable flavors in nonalcoholic juice beverages over time
To determine the effect of honey on maintaining color stability over time
To determine processing parameters which produce microbiologically stable products
To describe (where possible) the mechanism(s) by which honey may affect mouthfeel, flavors, flavor modification or potentiation, clarity, color and microbial stability and potential methods to overcome any adverse effects encountered in product formulation
To determine consumer acceptance through sensory analysis

Phase 1: Formulation

Beverage Formulation

Cranberry juice and lemonade-type beverages were developed. Both beverages were formulated with fruit juice as a base. Each juice drink contained vitamin C and the tart flavors were a pleasant complement to the sweetness of honey. The botanicals used in the cranberry juice-based beverage were guarana and ginseng. Guarana has a high caffeine content, providing a “boost” to the central nervous system, while ginseng provides a counter effect and produces an adaptogenic effect. The lemon juice beverage contained chamomile, which produces a calming effect.
The juice-based beverages were diluted to a lower percent soluble solids content (oBrix) with distilled water. Concentrated, unsweetened cranberry juice (oBrix: 50 ±0.1) was diluted to standard strength (oBrix: 7.5). Unsweetened, single-strength lemon juice was used. Both beverages were sweetened with liquid, grade A, white clover honey and combined with botanical extracts. Extensive flavor development in both beverages was
necessary. Several flavors were evaluated before finalizing the finished prototypes (Tables 1 and 2).

The colors of the guarana and ginseng extracts were very dark and did not present a problem in the dark-colored cranberry juice. However, in the lighter-colored lemon juice beverage, the chamomile extract turned the beverage a dark, gray-brown color. A fluid extract of chamomile (a much lighter-colored extract) was obtained and the color problem was resolved. The standard extracts of guarana and ginseng were extremely concentrated, requiring preparation of stock solutions to facilitate handling and weighing. Concentration of standard ginseng extract is 5:1 or 5x. According to recommendations from the botanical manufacturer, the target level for ginseng is 3000 milligrams per 10 ounce serving of juice beverage. Therefore, a 1x concentration stock solution was developed (four parts water were added to one part extract).

Standard guarana extract contains 10% caffeine. The target level for guarana is 250 to 500 milligrams per serving, or 2.5 milligrams to 10milligrams of caffeine per serving. Therefore, the guarana was diluted to !% caffeine (1 part standard extract to 9 parts water). The amount of stock solution used was based upon the dilution and desired target levels.

Beverage production

During the formulation phase, the beverages were mixed cold and held refrigerated until evaluation. However, for shelf life studies the beverages were mixed and pasteurized. Prior to mixing with water, flavors and botanicals, the honey was heated to facilitate blending. The blended beverages were pumped through a coil pasteurizer, using a Masterflex pump, and heated to 165 °F. The processing temperature of 165 °F was determined in relation to the pH of the prototypes and was sufficient for pasteurizing both beverages. The pasteurized product was filled hot into clean, eight-ounce glass jars. The jars were capped using a plastisol-lined cap, inverted and allowed to cool. The processed samples were stored upright in the dark at 70 ºF.

Phase II: Shelf-Life Studies

Shelf-life studies were conducted to evaluate color, pH, percent soluble solids, clarity, sedimentation and microbial stability. The two honey-sweetened juice-based products were processed and stored for 6 months at 70 ?F in the dark.
Samples were evaluated and analyzed in triplicate at day 0, 3 months (90 days) and 6 months (180 days).

Color analysis and results

Beverage color was evaluated using a Minolta Chroma Meter CR-300 programmed for the Hunter Lab Color System (Minolta Corporation, Instrument Systems, Ramsey, NJ). The Hunter Lab Color system determines values for
perceived color. Lightness is expressed as a “L” value, while “a” and “b” values indicate chromaticity coordinates. Lightness was expressed as dark to light with 0=black and 100=white. Green to red was expressed by the “a” value. A more positive value represented red, while a more negative value represented green (-80=green, 100=red). Blue to yellow was expressed by the “b” value. A more positive value represented yellow and a more negative value represented blue (Tables 3 and 4).

pH analysis and results

An Orion ionAnalyzer, model EA 920, with a Ross Sure-flow combination glass body electrode, was used for pH studies (Table 5). The Ross Sure-flow electrode provided a free-flowing sleeve junction designed for measurements of viscous or colloidal samples. The pH meter was calibrated utilizing standard solutions of pH 7.0 and 4.01. As expected, pH of the beverage systems did not change during storage.

Percent Soluble Solids Analysis and Results

Percent soluble solids (refractive index) of the beverages samples were measured in °Brix using a ReicherJung hand-held refractometer (model 10431,
Cambridge Instruments, Buffalo, NY). Brix (range 0-50 degrees) was measured in sucrose equivalents by placing a drop of sample on a prism. Refractometry is when a ray of electromagnetic radiation strikes a flat surface at an angle. The ray may be bent upward (reflected) or bent downward (refracted). The amount of refraction defines the concentration of a solute in a solution. The refractive index of the lemon and cranberry juices did not change in both beverage systems during storage (Table 6).

Clarity analysis and results

Clarity of juice samples was evaluated with a Lambda 3 Double-Beam UV-Visible Spectrophotometer (a electoroptical mechanical instrument utilizing a reflecting Littrow monochromator, Perkin Elmer, Norwalk, CT). The spectrophotometer was set at 650 nm wavelength. Distilled water was used as a reference for zeroing. Samples were placed in cuvettes, inserted into the sample port and measurements were recorded. Clarity was not effected in the lemon and cranberry beverages during storage (Table 7).

Sedimentation Analysis and Results

Sedimentation was analyzed by measuring the thickness of sediment at the bottom of beverage containers (beverage samples were stored in eight-ounce clear glass containers). The amount of sedimentation increased for lemon and cranberry samples over time (Table 8). The greatest amount of sedimentation was observed on day 180 for both beverages. However, less sedimentation was found in the lemon-based beverage.

Microbial Analysis and Results

Beverage samples were analyzed for lactic acid content and yeast and mold
growth during six-month storage. Microbial analysis provides valuable information about the effectiveness of pasteurization in beverage production and the effect of time on beverage stability. As expected, microbial counts for all test dates were below detectable levels, indicating the beverage systems were stable during storage. Results revealed there was minimal microbial load present in the fruit beverages (Tables 9 and 10).

Results for Honey Lemon Beverage

*One of the triplicate samples resulted in an unusually high value. The other two samples resulted in zero yeast growth.

Phase III: Sensory Analysis

A modified hedonic scale was used to determine overall liking and acceptability of appearance, texture, flavor and overall acceptability in the lemon and cranberry beverages. Beverage samples were also evaluated for specific attributes such as lemon and chamomile flavors (lemon-chamomile beverage) or cranberry flavor (cranberry beverage). Two sensory panels analyzed 2 samples of each beverage on test days–giving a total of 4 replications. Significant differences (p?0.05) were found in the general flavor and the chamomile flavor for the honey, lemon-chamomile beverage. The flavor attribute was found to be more acceptable on day 90. On day 180 the flavor acceptability decreased to that found on day 0. The acceptability of the chamomile flavor increased (p?0.05) on day 90 and this level of acceptability was still present on day 180. All other attributes increased numerically on day 90 and then decreased on day 180. However, the values were not significantly different (Table 11). The data indicate optimum storage time at 70 ?F for the lemon-chamomile beverage was 90 days.

*Where 9=like extremely, 5=neither like nor dislike and 0=dislike extremely. Means with different number superscripts in a column are significantly different at p=0.05.

Appearance was the only attribute that indicated a significant loss (p>0.05) of acceptability over storage time in the cranberry beverage. All other attributes demonstrated the same trend as seen in the lemon-chamomile beverage Acceptability was optimal on day 90 of storage. The differences in the cranberry
beverage were all significant (p>0.05) over time (Table 12).

Conclusions

Honey-sweetened, nonalcoholic beverages combined with botanicals were successfully produced. Shelf-life studies revealed very little change in beverage color, pH, percent soluble solids and clarity during six month storage. The amount of sedimentation increased in both beverages over time. However the lemon-chamomile beverage had less sedimentation compared to the cranberry beverage. Both beverages were microbiologically stable during storage. Sensory analysis revealed the lemon-chamomile and cranberry juice drinks were acceptable for 180 days, with the highest degree of acceptability at 90 days.