3. Quality Control Aspects of No and Low (NoLo) Alcohol Products
3.1. Microbial Ecology
NoLo alcohol products are more susceptible to microbial contamination due to their low alcoholic strength and the presence of fermentable sugars
[14][15]. A large number of lactic acid bacteria, coliforms, moulds, and yeasts cause spoilage, as they can use the carbohydrate content for fermentation processes producing undesirable changes in them. Acids, alcohols, and diacetyl are examples of fermentation by-products that impact the organoleptic quality of the beverages. This deterioration is also accelerated by the sugar used as a sweetener
[14]. NoLo alcoholproducts are, therefore, typically either heat-sterilized or aseptically packaged and should have stability similar to that of other alcohol-free beverages, such as fruit juices or caffeinated soft drinks.
3.2. Alcoholic Strength and Chemosensory Perception
As a precursor to flavour-active esters, ethanol enhances some flavours, such as those that result in a sweet taste. In addition to warming the olfactory tissues, ethanol is recognized to have a significant influence on the development of the distinctive background flavour of beer
[9]. In NoLo alcohol products, a partial loss of flavour is unavoidable because ethanol is eliminated using various dealcoholisation techniques
[9][16]. Ethanol has a considerable impact on the flavour release of alcoholic beverages and subsequent chemosensory perception. Discrimination of alcoholic strength by taste has been shown to be only partially possible in a range of intermediate alcoholic strengths and is not possible at higher concentrations
[17][18]. Alcoholic beverages′ scent, taste, and mouthfeel might be perceived differently by consumers depending on the amount of ethanol in the beverage
[19]. The perception of worty taste is diminished due to ethanol′s increased aldehyde retention. Conventional beers retain aldehydes at a rate of 32–39% as compared with 8–12% in alcohol-free beers
[10].
3.3. Higher Alcohols
Higher alcohols, also known as fusel oils, occur in fermented alcoholic beverages. The concentrations of these alcohols are dependent on the efficiency of amino acid uptake and sugar utilization by the yeast
[20]. Higher alcohols are classified into aliphatic and aromatic alcohols. The main aliphatic higher alcohols are 1-propanol, isobutanol, amyl alcohol, and isoamyl alcohol, while the main aromatic higher alcohols are 2-phenylethanol, tyrosol, and tryptophol
[21].
1-Propanol, isobutanol, and isoamyl alcohols make up most of the aliphatic higher alcohols that contribute to the aroma and warmth of beer
[9][21]. 1-Propanol and 2-methylpropanol can contribute to the “rough” flavours and harshness of beer, while amyl alcohols contribute to the “fruity” qualities
[22]. When the isobutanol concentration exceeds 20% of the combined concentration of three alcohols (1-propanol, isobutanol, and amyl alcohol), it has a negative impact on beer quality
[23]. In contrast to the disagreeable odours created by tyrosol and tryptophol, the aromatic alcohol 2-phenylethanol imparts “sweet” or “rose” qualities into beer
[21][22].
In particular, spirit-similar beverages made with added flavours are currently not expected to contain higher alcohols. However, flavour mixes of the higher alcohols representing a specific type of spirit might be conceivable. Fusel alcohols in NoLo alcohol products, if they do not exceed the levels currently reported to naturally occur in their alcohol-containing counterparts, are likely not to pose an inherent health risk to consumers
[24].
However, as mentioned in
Section 2 above, higher alcohols may contribute to alcoholic strength; therefore, at least for “zero” or “no” alcohol products, the product formulation must also exclude these components. For low-alcohol products, the level of alcoholic strength that includes both ethanol and higher alcohols must stay below the threshold of the respective jurisdiction.
Although there are some quality characteristics of alcohol-free beer that are similar to those of conventional beer, such as pH, colour, and turbidity, there are notable changes in the olfactory components, such as alcohols, aldehydes, and esters. Unfortunately, the absence of aroma components may result in products that consumers find to be sensory unacceptable; however, recently, the sensory quality in the category has improved considerably, for example, by blending beer from stopped fermentation (which is rather sweet) with beer from distillation-type dealcoholisation.
3.4. Sugar Content
Alcoholic beverages can contain significant amounts of sugar
[25]. Beyond alcohol-related health risks, other considerations of health policy are the health risks caused by excessive sugar consumption. Sometimes, substitution of alcohol with sugars may occur in NoLo alcohol products. (e.g., in the category of alcohol-free beers, manufactured using stopped fermentation, or in some alcohol-free spirits on the market, which are mostly coloured and flavoured sugar-water
[17]). The amount of total carbohydrates in alcohol-free beers is typically about twice that of alcohol-containing beers. The net reduction in calories may still be significant. This can be explained by the fact that alcohol contains almost twice as many calories per gram as carbohydrates and proteins
[8]. For example, in a sample of more than 1200 German beers, the average energy was reduced by almost half from 181 kcal/100 mL (alcohol-containing beers) to 98 kcal/100 mL (alcohol-free beers)
[26]. Nevertheless, the net public health effects of alcohol are much higher than those of sugar; therefore, some substitution of alcohol with sugar would probably still be advantageous from a public health standpoint.
However, higher sugar levels could discourage some consumers from switching to NoLo alcohol products. Sugar reduction strategies are necessary to influence consumer choices. It remains to be seen whether consumers will willingly choose high sugar content over high alcohol content. There is clearly much room for product development, including sugar-free NoLo alcohol products.
Another aspect of the balance between sugar and alcohol is the isotonicity of the beverages. Although alcohol-containing beers generally are in the hypertonic osmolality range, many alcohol-free beers fall into the preferable isotonic range, making the products interesting, for example, to restore the strength of people who perform strong physical exercise
[27].
3.5. Other Compounds of Public Health Concern
In addition to ethanol, other constituents of alcoholic beverages pose potential health risks to consumers. The contamination of raw materials with mycotoxins
[12][13][28], such as aflatoxins and ochratoxin A, is another potential concern for the derived NoLo alcohol products, especially in temperate and tropical regions. However, this can be mitigated by adapting good agricultural practices to keep contaminants as low as reasonably achievable. Similarly, heavy metals such as iron, lead, copper, or zinc can occur in NoLo alcohol products. Other volatile compounds, such as acetaldehyde and methanol, are potential contaminants worthy of monitoring in alcoholic beverages. Therefore, the appropriate preventive measures already existing for conventional alcoholic beverages can help to control and minimize the occurrence of these contaminants.
4. Quality Control Technologies of No and Low (NoLo) Alcohol Products
Globally, there are regulations for various compounds in beverages and foods; therefore, there is a need for methods to control levels. The main objective of fit-for-purpose analytical technologies would, firstly, be to determine the alcoholic strength, as this is the main marketing claim on the beverages. Additionally, it would be worthwhile to determine other constituents that impact consumers health and influence consumer choices.
Currently, there are no available methods that are specifically related to NoLo alcohol products, but typically all methods available for alcoholic and alcohol-free beverages can be used. The methods to determine alcoholic strength must be tested, if the sensitivity is sufficient for the needed lower levels, but in the researchers′ experiences regarding official alcohol control, densimetric methods (such as oscillation-type electronic densimetry) for determining the EU requirements can determine alcoholic strength with one decimal place
[8] as low as 0.0% vol. (which mathematically would be less than 0.04% vol.). Therefore, the limit of detection of the method should not be higher than this level (i.e., 0.04% vol. for controlling a level of 0.0% vol).
In the researchers’ experience, more modern methods than densimetry, such as nuclear magnetic resonance (NMR) spectroscopy, can also be used for non-destructive determination of constituents of NoLo alcohol products, since they have been previously used for identification and quantitation of multiple compounds. In a study, 36 different ingredients (i.e., sugars, flavourings, sweeteners, organic acids, alcohols, and vitamins) were successfully identified and quantified in alcohol-free beverages
[25][29]. Moreover, since NoLo alcohol products are known to have a high sugar content, proton NMR could provide a rapid and efficient technique to monitor the sugars, namely fructose, glucose, and sucrose
[25].
Other mainstream techniques for the analysis of beverages are still useful. The techniques range from simple pycnometry to advanced chromatography, sensory analysis, and spectroscopy
[25][30][31][32][33][34][35]. The applications can be customised to analyse physicochemical and sensory attributes as necessary. There are excellent research on analytical techniques applied to the analysis of alcohol and non-alcoholic beverages
[36].
5. Labelling of No and Low (NoLo) Alcohol Products
Labelling of NoLo alcohol products is discussed in more detail in a separate Special Issue research
[37]. In brief, information on the ingredients is necessary for health-conscious consumers to choose the beverages. A declaration of ingredients and nutrients is crucial to provide consumer information about the product. For NoLo alcohol products, it is critical that producers provide consistent nutritional information, including details on the content of ethanol, total carbohydrates, and any other additives that impact consumer health. This would also refer to other alcohols, in addition to ethanol, that may cause relapse due to alcohol-related stimuli in abstinent persons with former alcohol dependence
[38]. Currently, there is no specific legislation for NoLo alcohol products, apart from the general food information requirements necessary for any category of food
[8].
The fundamental justification for including NoLo alcohol products in global legislation is that they are thought to offer considerable health benefits if alcohol consumption is partially or fully substituted. Nutritional labelling has been suggested to be a strategy to help people choose foods that are advantageous for them to buy and eat
[39].
There may be a comparable level of concern about the lack of adequate health information on NoLo alcohol products, given the typical lack of appropriate nutritional labelling on alcoholic beverages. Research has even proven that beverages with an alcoholic strength of 0.5% vol. or less have no physiological effects on the body and cannot cause intoxication
[11]. However, low-strength products of up to 1.2% vol. may pose hazards, particularly for pregnant women and those with underlying medical problems, or persons in abstinent remission of alcohol use disorders
[40][41][42][43]. Such health implications should be stated on the label.