1. Introduction

Sorghum (Sorghum bicolor (L.) Moench) is a gluten-free, cereal crop cultivated globally. In regions of the world such as north-west and south-central Africa, sorghum grain is traditionally consumed in staple foods, whereas in Western countries it is typically used in animal feed for domestic use or export, and to a much lesser extent in human foods [1]. The ability to grow sorghum in rain/temperature-variable climates, even in regions experiencing significant water scarcity, exemplifies sorghum’s potential to contribute to sustainable agriculture and food security around the world [2].

Nutritionally, sorghum is important due to its association with disease-mitigating mechanisms, notably those underpinning the development of cardiovascular disease, diabetes mellitus and some types of cancer [3,4]. The current evidence base, as appraised in a recent systematic literature review [5], indicates improvements in markers of oxidative stress, control of blood glucose and lipid levels. These benefits, along with enhanced satiety and appetite regulation relevant to weight management, appear particularly evident when wholegrain sorghum foods are consumed regularly. Experimental animal and cell-line research also provides evidence for favourable cell-mediated immune responses, including antioxidant and anti-inflammatory effects, particularly for polyphenol-rich red and brown sorghum grain [6]. Regular consumption of sorghum grain is needed for consumers to gain its purported health benefits. However, this can be difficult to achieve in societies where sorghum is not consumed traditionally, such as in Australia and China, and the sorghum-containing product range is limited [7,8]. Despite relatively limited utilisation, sorghum production in both Australia and China operates at a material and economically significant scale. Between 2020 and 2024, Australian sorghum production ranged from 397 thousand tonnes (kT) in a drought year (2020) to 2,648 kT in 2022, corresponding to annual values of US $105–704 million. Over the same period, China’s production remained relatively stable at 2,954–3,379 kT, with annual values of US $924–1,116 million (FAOSTAT, https://www.fao.org/faostat).

In countries with a limited range of sorghum-containing food products, more investment in food innovation is required to increase the volume and variety of sorghum-containing food products available to consumers. This must be done with consideration of consumers’ expectations of what constitutes healthy cereal-based foods. Consumer research indicates that the perceived healthiness of cereal foods, which is likely to drive consumer purchases, is associated with greater wholegrain, dietary fibre, and antioxidant contents, as well as lower levels of salt and fat [9]. From a nutrition science perspective, the beneficial, synergistic effects of the germ and bran fractions of wholegrains are typically implicated in health benefits associated with cereals, given they are high in dietary fibre, healthy lipids, micronutrients, and phytochemicals [10–12]. Sorghum-based food products can be made to possess these characteristics, and hence to be marketed as ‘healthy’, as well as ‘gluten-free’; however, attention must be given to the impact of processing methods on the health-enhancing potential and sensory appeal of end-products [13,14]. Monitoring progress towards greater sorghum-based product expansion and food innovation in Western societies requires regular evaluation of the prevalence of sorghum in products available to consumers, particularly within widely consumed supermarket product categories. As current monitoring largely focuses on production and trade metrics, food product audits are critical and provide an effective indicator of market uptake and dietary exposure [15,16]. Breakfast cereals and grain‑based snack bars are particularly relevant categories for this purpose due to their high population reach, routine consumption, and platforms for food innovation using alternative grains [17], and supermarkets serve as the dominant retail channel for these products. A world-first (to our knowledge) study of sorghum prevalence was conducted in 2020 through a cross-sectional audit of Australian supermarkets [18]. Sorghum ingredients were found in only 6.1% of ready-to-eat breakfast cereals and 2.0% of snack bars. The audit was limited to these two food categories in major supermarkets, and excluded smaller, specialty food retail outlets, posing a limitation given that innovative foods with lesser-known ingredients such as sorghum are more likely to be sold in such stores [18]. The 2020 audit provided important baseline data, with the authors recommending expansion to other categories in future audits to measure the prevalence in a wider range of food products. To date, no systematic supermarket audit has been conducted in China. Although sorghum grain is reported to be present in an expanding range of food products in Chinese supermarkets, including bread and noodles [19], this has not been empirically substantiated. Investigating the applications of sorghum in Chinese food products could offer valuable insights into how sorghum grain is utilized in this market and help drive demand for sorghum, supported by sorghum growers and the food industry globally.

The main aim of the present study was to examine the prevalence of sorghum in a range of grain-based food products in a cross-section of supermarkets in China and Australia. A secondary aim was to compare trends observed in the present audits to the previously mentioned, seminal Australian audit conducted in 2020.

2. Materials and methods

2.1 Overview of research methodology

The research methodology used in this study is represented schematically in Fig 1. Key stages of in this workflow are (1) selection of the grain-based food product categories, (2) the audits in China and Australia, (3) the identification of sorghum-based products, (4) data collection from the product labels, and (5) the analysis of the data and comparisons between datasets. Completion of all stages of the workflow allowed both the main aim and the secondary aim of the study (see previous section) to be achieved. The methodology adhered to standards that allow for research reproducibility, allowing valid comparisons to future studies.

Download:

• PNG
  larger image
• TIFF
  original image

Fig 1. Research methodology used in this study.

https://doi.org/10.1371/journal.pone.0349203.g001

2.3 Product selection

Product categories were selected on the basis that they contained grain-based foods. In China, breakfast cereals and snack bars were selected for analysis, as per the 2020 audit conducted in Australia [18]. Time constraints did not make it feasible to extend the audit beyond these two categories. In the present Australian-based audit, breakfast cereals and snack bars were also included, along with flour, pasta and noodle products, as these categories represent additional potential sources of sorghum in the Australian food supply. Definitions for all breakfast cereal subcategories applied in the classification and analysis are presented in Table 1, while definitions for snack bars are provided in Table 2.

Download:

• PNG
  larger image
• TIFF
  original image

Table 1. Definitions of breakfast cereal subcategories.

https://doi.org/10.1371/journal.pone.0349203.t001

Download:

• PNG
  larger image
• TIFF
  original image

Table 2. Definitions of snack bar subcategories.

https://doi.org/10.1371/journal.pone.0349203.t002

3. Results

In this study, a total of 1,692 products were evaluated across five different grain-based product categories in China and Australia. In China, 737 food product items were analyzed. Of these, 279 items were categorized as breakfast cereals, while the remaining 458 items were categorized as snacks. In Australia, a total of 955 products were audited, and of these, 356 were breakfast cereals, 285 were snack bars, 80 were flours, 59 were noodles, and the remaining 175 products were pastas.

3.1 Breakfast cereal audit in China

Of the total 279 breakfast cereal products audited in China, porridge-style cereals were most frequently identified (n = 93, 33.3%), followed by bubbles/puffs/flakes (n = 76, 27.2%), and muesli (n = 69, 24.7%) (Table 3). Flaked biscuits and granola comprised the remaining cereal product types (10%). Only 12 (4.3%) of the 279 cereals examined, contained sorghum across a range of breakfast cereal types, including porridge (n = 5), bubbles, flakes and puffs (n = 3), muesli (n = 3), and flaked biscuits (n = 1) (Table 3).

Download:

• PNG
  larger image
• TIFF
  original image

Table 3. Summary of sorghum-containing breakfast cereals in major supermarkets in Shenzhen, China (February 2023), and major supermarkets and a smaller health food store in the Illawarra region of New South Wales, Australia (April 2024). Data are presented as counts (n) and percentages (%).

https://doi.org/10.1371/journal.pone.0349203.t003

Of the sorghum-containing breakfast cereals identified, only 1/12 listed sorghum in the first position of the ingredient list. Sorghum was listed second in the ingredient list in 2/12 of the products, and in the third position or beyond in 9/12 products. The most common sorghum ingredient in the ingredient list was sorghum flour (5/12), followed by wholegrain sorghum (3/12), sorghum (3/12), and organic sorghum (1/12). Eight of the 12 (66.7%) sorghum-containing breakfast cereal products had wholegrain sorghum listed as an ingredient, while the remaining products did not specify whether the grain/flour was wholegrain. As a percentage of the total surveyed breakfast cereals, sorghum was most frequently used in porridge (1.8%), followed by muesli and bubbles/puffs/flakes (1.1%, respectively) (Table 3). A total of seven out of 12 sorghum-containing breakfast cereals were gluten-free, and three out of 12 were marketed towards children and were made with wholegrain sorghum. Most of the sorghum-containing breakfast cereals (9/12) were in the health food section of the supermarket. Only three out of 12 of the sorghum-containing breakfast cereals mentioned ‘sorghum’ on the front-of-pack label, with the remainder mentioning ‘sorghum’ only in the list of ingredients or in small font on the back of the pack. All 12 sorghum-containing breakfast cereals included additional descriptors such as ‘organic sorghum’, ‘sorghum rice’, ‘sorghum flour’, or ‘puffed sorghum’.

3.3. Snack bar audit in China

A total of 458 snack products were analyzed in eight subcategories (Table 4). Only 2.0% (9/458) of the snack bar products contained sorghum as an ingredient. Of these, three were classified as biscuit bars (33%), two as muesli/cereal bars (22%), two as puff/bubble bars (22%), one as oat bake bars (11%), and one as a rolled-oat bar (11%).

Download:

• PNG
  larger image
• TIFF
  original image

Table 4. Summary of sorghum-containing snack bars in major supermarkets in Shenzhen, China (February 2023), and in major supermarkets and a smaller health food store in the Illawarra region of New South Wales, Australia (April 2024). Data are presented as counts (n) and percentages (%).

https://doi.org/10.1371/journal.pone.0349203.t004

The utilization of sorghum varied across the different types of snack bars. In biscuit-style bars, muesli/cereal-style bars, and oat bake-style bars, sorghum was incorporated in formulations as ‘sorghum flour’ or ‘wholegrain sorghum’. Sorghum was identified in the 8^th or higher position in the ingredients list. However, in the other categories, ‘puffed sorghum’ was listed in the ≥ 5^th positions in the ingredients list, and the product descriptor included ‘puffed product’.

Food manufacturers did not specify whether or not wholegrain sorghum ingredients were used in the bars. All sorghum bars were labelled gluten-free, with 3/9 (33%) marketed toward infants and children. Although none of the snack bars mentioned sorghum in their product names, some displayed sorghum on the front-of-pack labels. Additionally, none of the sorghum-containing snack bars included the term ‘ancient grain(s)’ in their ingredient lists across all subcategories.

3.6 Sorghum prevalence in breakfast cereals and snack bars in supermarkets in China and Australia

Among the breakfast cereal (Table 5) and snack bar (Table 6) subcategories analyzed, there were no significant differences in sorghum utilization between China and Australia (Fisher’s Exact Tests, p < 0.05), except for oat bake snack bars, of which one (of 31) were from China and seven (of 24) from Australia (p = 0.0265).

Download:

• PNG
  larger image
• TIFF
  original image

Table 5. Fisher’s exact tests of sorghum prevalence in breakfast cereals in supermarkets in China (February 2023) versus Australia (April 2024). Data are derived from Table 3.

https://doi.org/10.1371/journal.pone.0349203.t005

Download:

• PNG
  larger image
• TIFF
  original image

Table 6. Fisher’s exact tests of sorghum prevalence in snack bars in supermarkets in China (February 2023) versus Australia (April 2024). Data are derived from Table 4. Contingency tables are 2 × 2. An asterisk highlights p values < 0.05.

https://doi.org/10.1371/journal.pone.0349203.t006

4. Discussion

In this cross-sectional study, we investigated the utilization of sorghum in grain-based food products across food retail outlets in China and Australia. To our knowledge, this study represents the first benchmarking of sorghum’s prevalence in cereal-based food products in China, and builds upon prior research in Australia that included a seminal audit conducted in 2020 [18]. Overall, sorghum prevalence in Chinese breakfast cereals and snacks was similar to that observed in Australia, with sorghum identified in 8.3% of 279 breakfast cereals and 2.0% of 458 snack bars audited in China, compared to 6.2% of 356 breakfast cereals and 3.2% of 285 snack bars in Australia (refer to Table 3). The Australian findings represent a slight rise from 6.1% for breakfast cereals and 2.0% for snack bars in 2020 [18]. The review of pastas, noodles and flour products reflects an expanded audit undertaken exclusively within Australia and should not be interpreted as part of any cross-country comparisons. Notably sorghum was not identified in any formulations within these product categories.

We wish to emphasize that since the sorghum-containing products were rare (e.g., only 12 out of 279 breakfast cereals in China and 22 out of 356 in Australia), the sample size is very small, resulting in low statistical power and a high risk of type-II error (failure to detect a real difference). Therefore, in this study, a conclusion that no significant difference was found cannot be used confidently to imply that no difference exists.

In China, approximately one-third of sorghum-containing breakfast cereals were identified in the porridge subcategory (refer to Table 3). In Australia, sorghum was more commonly found in ready-to-eat extruded breakfast cereals (refer to Table 3). In China, porridge is often prepared using a powdered or paste base that is mixed with milk or water, offering a novel format with potential applicability in Australian markets. In these mixtures, sorghum is typically combined with other grains such as corn, barley, and red bean to create a porridge-type product. Whether this type of product could serve as a viable breakfast cereal alternative for Australian consumers requires further testing and validation by food manufacturers willing to explore new product developments.

The breakfast cereal markets in both China and Australia have experienced significant growth due to increasing consumer interest in healthy and nourishing ready-to-eat breakfast options. From 2012 to 2017, the market in China showed a yearly growth rate of 10.2% [20], and it is projected to reach a revenue of US$1.32 billion in 2024 [21]. This high demand presents an opportunity for commercial success in the breakfast cereal market by expanding the sorghum breakfast cereal product range in both countries. Targeting young people aged between 2 and 18 years old may be a key strategy for sorghum food innovators and research and development, given that 44.1% of all wholegrain products annually are consumed by this group in Australia [18,22]. In China, grain foods are staples in the diets of consumers across all age groups and typically include rice and wheat products (such as noodles and steamed buns), but the prevalence of sorghum in these commonly consumed foods is currently unknown. Noodles and pasta products were reviewed in the Australian audit presented in this paper, but sorghum was not identified in any formulations.

Compared with breakfast cereals, sorghum prevalence in snack bars was observed to be lower in both China and Australia (refer to Table 4), likely due to the significantly smaller snack bar market relative to the breakfast cereal market in these countries [23,24]. Snack bar formulations in China were largely comprised of sorghum flour, which is produced by milling sorghum grain to formulate different types of snack bar formats, including the more popular biscuit-style and rolled oat-style bars. These applications appear to be an extension of traditional Chinese foods, such as mantou, offering potential ideas for novel product innovation in this category in Australia.

Although sorghum flour was identified in the snack bar products in China, it was rarely the dominant or characterizing ingredient. In the biscuit-style snack bars, it typically comprised about 5% of the ingredients, alongside other grains like oats (≥ 5%) and corn (≥ 5%). In the Australian audit, nut bars were observed to still dominate since 2020, potentially explaining the low prevalence of sorghum in this category [18]. Like in China, the sample of sorghum-containing snack bars comprised mostly sorghum flour, followed by sorghum flakes then puffed sorghum. This contrasted with the 2020 audit, where sorghum flour was not listed in the ingredients list of any snack bars in Australia, and puffed sorghum was most common [18].

The marketing of sorghum in both breakfast cereals and snack bars is limited in both countries. For example, in Australia, only two of the snack bars included ‘sorghum’ on the packaging, and it was listed for its texture contribution rather than its health effects. The inclusion of sorghum on the front-of-packaging would be a step in the right direction to increase consumers’ awareness of sorghum, as lack of recognition has been identified as a major barrier to acceptance of sorghum as a human food [7].

In China, the healthier sorghum-containing snack bars, characterized by higher contents of wholegrain and/or fibre and low or no added sugars, tended to be marketed towards children and younger people. Examples of these products included wholegrain sticks and brown rice crackers. In contrast, in Australia, there were no sorghum-containing snack bar products targeted towards children, despite being a convenient and easy lunch box option. According to the earlier Australian audit [18], manufacturers of the grain-based snack bars may have little motivation to explore new formulation ideas, such as using sorghum alongside more fibre and less sugar, due to their strong market position with current offerings. However, demonstrating other food successes in other markets, such as in China, may stimulate ideas for new product development to increase market share in Australia. Furthermore, wholegrain sorghum was not listed in the ingredients of any snack bars containing sorghum in Australia, nor was there a wholegrain claim displayed, despite wholegrain claims generally being used more frequently on Australian food products [25]. Research by the Grains and Legumes Nutrition Council of Australia indicates that Australian consumers do not prioritize consumption of wholegrains, despite having an awareness of their potential health benefits [26], implying that marketers may not be interested in leveraging wholegrain claims to drive consumer purchases in the snack bar product category.

Differences in the availability and types of sorghum‑containing products may reflect underlying cultural and economic influences. In Australia, sorghum has a long history as a locally grown grain used predominantly in livestock feed, with recent growth in consumer‑oriented applications linked to health‑focused marketing and interest in gluten‑free products [7]. In contrast, Chinese grain consumption patterns are shaped by longstanding cultural preferences for rice, wheat‑based noodles, and traditional coarse grains such as millet, which may reduce consumer familiarity with sorghum as an ingredient [19]. These cultural and economic contexts likely contribute to differences in product development and category representation observed between the two markets. To support broader utilization across settings, cross‑cultural consumer education that raises awareness of sorghum’s culinary uses and nutritional attributes, led by chefs in restaurants, grain advocacy groups, and health professionals (notably dietitians and nutritionists), may be an effective strategy.

A cross-section of specialty health food retailers was intended to be included in the Australian audit presented here; however, only one store agreed to be involved. Despite this, important insights were afforded by this single site. Although sorghum was not found in any breakfast cereals, snack bars, flours, pastas or noodles, the diversity of product offerings reflected more specialized, health-focused products, particularly in the breakfast cereal and flour categories. These findings suggest potential for sorghum’s incorporation into novel formats. Expanding future audits to include more health food and specialty shops could provide a more comprehensive understanding of emerging trends. Including gym and fitness stores, which cater to health-conscious consumers, may further reveal opportunities for sorghum innovation. Also, future audits should focus on ethnic food specialty stores, especially to capture people from cultural backgrounds that use sorghum in traditional cooking, such as people from African and Indian communities. The bread category should also be audited in future across a variety of retail outlets, including supermarkets, specialty food stores and bakeries, as bread is the most frequently purchased grain food in Australia after refined pasta and rice [26].

Future opportunities for sorghum food innovation in both China and Australia should leverage the potential health benefits and food attributes associated with wholegrains broadly. Consumer preferences in both countries are shifting towards health-conscious and diet-focused choices, with many consumers willing to pay a premium for perceived health benefits [27,28]. The rising demand for gluten-free products has also opened opportunities for smaller producers, driving innovation and competition [29]. The healthy breakfast and snack food market will likely grow in response to increased demand for convenient, health-oriented products. Wholegrain foods, particularly those with a low glycemic index, have also gained popularity [30], presenting opportunities for expanding sorghum-based offerings. The growing interest in plant-based diets [31] also positions sorghum as a viable ingredient for meeting these evolving demands, potentially increasing its acceptance and prevalence in human food supplies. Targeting young consumers (up to 18 years) in both countries presents an opportunity to expand the sorghum breakfast and snack bar cereal market, as this demographic contributes significantly to wholegrain consumption [22]. In China, sorghum is most recognized for its use in liquor production; however, during the auditing of products for this study, sorghum was also identified in cooking sauces and snacks (results not reported). This highlights sorghum’s versatility and potential for diverse applications [19].

The key strengths of this study include the rigorous methodology and cross-country analysis, which provided valuable insights into sorghum’s market presence. The large sample size and standardized data collection methods strengthen the study’s reliability. However, between-country differences in food labelling regulations and dietary preferences, as well as the inability to specify sorghum content due to labelling practices, constrained direct comparisons. The focus on popular, large‑format supermarkets and major chains was intended to maximise product coverage but may underestimate sorghum presence in smaller independent stores, convenience outlets, e‑commerce platforms, or region‑specific retailers. Accordingly, cross‑setting comparisons were limited to contextualising differences rather than implying real‑time equivalence or national representativeness.

Temporal mismatch may also be perceived as a limitation. The China (February 2023) and Australia (April 2024) audits were conducted approximately one year apart; however, each audit was intentionally designed as a snapshot of the market at a specific point in time, rather than as synchronised assessments intended for real‑time cross‑country comparison. The two markets differ in retail structure, product turnover, cultural grain preferences, and the pace of new product development, and the study was not designed to evaluate tightly aligned market dynamics across settings. Accordingly, cross‑country observations are framed cautiously to contextualise differences rather than imply concurrent equivalence.

Limited access to health food and speciality shops in Australia also restricted the scope of the audit. The findings from Shenzhen may have limited generalisability to other regions of China, particularly northern and western provinces with different dietary patterns. Similarly, the Illawarra‑based Australian audit may not fully represent consumer purchasing environments elsewhere in Australia. Ethical considerations prevented the identification of specific brands or stores, and ingredient percentage data for sorghum was not always available, limiting the granularity of the analysis.

5. Conclusions

This study highlights a positive trend in sorghum’s integration into grain-based food products in China and Australia and identifies opportunities for further market penetration through innovation and education. Emphasizing sorghum’s health benefits and expanding its applications in novel and traditional formats can foster greater consumer acceptance and demand. Strategic product development, combined with targeted marketing focused on health benefits, can enhance sorghum’s appeal to consumers, fostering greater adoption in diverse food categories.

Future research should explore the nutritional and sensory benefits of sorghum-containing products and assess their appeal across diverse consumer groups. Expanding audits to additional food categories and evaluating new product formats could uncover further opportunities for sorghum innovation. Audits of specialty retailers, including those selling diverse ethnic foods as well as health food stores, would also provide a more comprehensive understanding of emerging trends and opportunities.

Supporting information

Acknowledgments

We acknowledge Cecily Ducksbury for guidance to Sophie L. Marsino in data collection. We thank Associate Professor Floris van Ogtrop (University of Sydney) for statistical advice.