Water kefir grains vs. milk kefir grains: Physical, microbial and chemical comparison

Abstract

Aims: Although kefir has been known for centuries, there is confusion between the two types of kefir grains, for example, milk kefir (MK) grain and water kefir (WK) grain. This study aimed to unravel the differences and similarities between WK grain and MK grain.Methods and Results: Microbiological analyses, identification of grains microbiota and enumeration of microbiological content of the grains as well as scanning electron microscope (SEM) imaging, dry matter, protein, ash, and mineral content, and colour analyses were carried out for the two types of grains. As a result, significant differences were found in microbiological content, chemical properties and colours (p < 0.05). Additionally, SEM images revealed the different intrinsic structures for the microbiota and the structure of the two types of grains.Conclusions: MK grain has more nutritional content compared to WK grain.Despite not as widely known and used as MK grain, WK grain is a good source for minerals and health-friendly micro-organisms such as lactic acid bacteria and yeasts.WK grain is possibly suitable for vegans and allergic individuals to fulfil nutritional requirements. Moreover, in this study, the variety of WK grain microbial consortia was wider than that of MK grains, and this significantly affected the resultant WK products.Significance and Impact of the Study: This is the first study that comprehensively compares two different kefir grains in microbial, chemical and physical properties.

Physical, chemical, and sensory properties of water kefir produced from Aronia melanocarpa juice and pomace

“…Furthermore, researchers reported that water kefir grains consisted of roughly 39% Lactobacillus sp., 31% Lactococcus sp. and 30% yeasts ( Gökırmaklı and Güzel-Seydim, 2022 ). All these studies reflect the fact that water kefir is usually made in an artisanal manner and the fermentation environment is generally variable.…”

Prophylaxis effects of water kefir on post‐infectious irritable bowel syndrome in rat model

“…There are previous studies that reported the effects of milk kefir against IBS (Seo et al ., 2018; Yılmaz et al ., 2019; Curciarello et al ., 2021). On the other hand, it was clearly explained in other previous studies that microbiota and metabolites of WK and milk kefir significantly differ (Guzel‐Seydim et al ., 2021; Gökırmaklı & Güzel‐Seydim, 2022). The ameliorative effect of WK against IBS was revealed in this pioneer study.…”

“…in the diet had the strongest influence (Dai et al ., 2013). Lactobacillus species, particularly Lactobacillus paracasei , L. hilgardii , and L. nagelii , are prevalent in WK (Gökırmaklı & Güzel‐Seydim, 2022). According to Marlicz et al .…”

“…The WK grains were added to the sugar solution and fermented for 48 h at room temperature (25 °C). In our previous study, the microbiota of WK grains was investigated (Gökırmaklı & Güzel‐Seydim, 2022). According to the study's findings, a variety of microorganisms, including yeasts, Bifidobacterium spp., Lactobacillus spp., Lactococcus spp., Streptococcus spp., Acetobacter spp., and Gluconobacter spp., were present in the WK grains.…”

Use of mandarin and persimmon fruits in water kefir fermentation

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Consumers are increasingly concerned about incorporating healthy foods into their diets, increasing the demand for probiotics, prebiotics, and functional fermented beverages. Water kefir is produced by fermentation of sugar solution with water kefir grains containing lactic acid bacteria such as Lactobacillus paracasei, Lactobacillus casei, Lactobacillus hilgardii, Lactobacillus nagelii, and yeasts like S. cerevisiae (Gökırmaklı & Güzel-Seydim, 2022). With potential health benefits, water kefir is gaining popularity as a fermented food using non-dairy substrates like vegetables, fresh/dried fruits, and plant-based milk.Thus, it also stands out as an important source of probiotics for both vegans and allergic individuals.

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