**1. Introduction**

High levels of meat consumption are associated with perceived health, social and environmental concerns resulting in calls to reduce the quantity of meat we consume [1]. To achieve a partial substitution of animal proteins in the diet with more sustainable plant proteins, long-term dietary transitions rather than short phases need to be established [2].

Studies have found that to create an effective dietary change, new practices should not diverge too much from consumers' previous behaviour [3]. Food choice has been recognised as a complex process that goes beyond sensory properties and involves many factors that can be grouped into the characteristics of the consumer, the product and the specific context in which the choice is made [4]. Factors related to consumer behaviour, which might limit consumer transition to alternative protein sources, are convenience and minimal cooking skills [5].

It is difficult to fully shift from a meat-centric diet to strict vegetarianism or veganism because of positive beliefs and attachments to meat and meat-centric societal constructs, however switching to a flexitarian or semi-vegetarian diet (mainly plant-based, with limited meat consumption) is less strict and can still have a positive impact [6].

A survey by the Humane Research Council [7] on 11,399 Americans found that 5 out of 6 people who become vegans or vegetarians eventually went back to eating meat. The authors suggest that it would be more important to persuade the majority of the population to reduce meat consumption rather than convincing a small percentage to give up meat completely [8].

Flexitarianism is increasing in popularity amongst consumers, with a market research study in the UK [9] reporting that while around 90% of consumers eat red meat or poultry, more than a third (34%) of eaters and buyers of meat and poultry have regular days when they avoid meat.

Within this context, the concept of hybrid meat products, that is meat products in which a proportion of meat has been partially replaced by more sustainable protein sources, might be suitable to bridge the gap between meat and meat-free products, while providing convenience, and allowing consumers to continue using foods as they would conventionally do [10].

Hybrid meat products could open new business opportunities for the food industry [11], and indeed very recently, hybrid meat products have started appearing in the UK market [12]. The meat industry might be answering the growing flexitarian consumer needs, but the launch of hybrid meat products might also be representing a moment for change and an attempt from meat manufacturers to gain additional market share over new popular plant-based alternative protein sources [8]. As Hicks et al. [13] point out, "it would be efficient and wise for the meat industry to build a strategy around the flexitarian demographic, to ensure their needs are met and to keep them consuming meat, rather than risk losing them to veganism".

We will now discuss the difference between hybrid meat products and meat extenders, provide a literature overview on consumer attitudes towards hybrid meat products and introduce the corpus linguistics (language analysis) techniques that will help achieve the aims of the current study.

Many processed meat products available in the market are already somehow "hybrid" as they often do not contain 100% meat [8]. For example in the UK, according to the Meat Products Regulation [14], only 42% of pork is needed to label sausages as pork sausages and the pork meat used can contain 30% fat and 25% connective tissue. A variety of functional ingredients have been traditionally added to processed meats, including fillers (plant substances with high carbohydrate content), extenders (non-meat compounds with considerable protein content), and binders (substances with high-protein content able to bind both water and fat) [15]. Indeed, plant-based ingredients from soy and wheat have been used by the meat industry to achieve cost savings [16], as well as for their functional properties: fat emulsification, gelling capability, and water binding [17].

The difference between hybrid meat products and meat products with plant-based functional ingredients (extenders, fillers and binders) is in the purpose of the mix of meat and plant proteins [8]. Usually plant-based functional ingredients are used traditionally for economic and technological reasons, in hybrid meat products this concept is pushed further to include positive connotations on the meat "extension", including healthiness, lower environmental impact and generally the idea of decreasing meat consumption [8].

Several research articles have shown that although challenging, it is technologically feasible to manufacture hybrid meat products such as burgers, meatballs and sausages with acceptable sensory quality [10,11,18,19]. However, consumer attitudes towards hybrid meat products have been investigated in a limited number of studies [8]. A study by de Boer et al. [20] compared hybrid meat products vs. alternative protein snacks such as insects, lentils and seaweed. The most popular snack was the hybrid one (chosen by 54% of 1083 participants). The authors concluded that it would be valuable to combine animal and plant-based protein and that hybrid meat products could be acceptable to lowly involved consumers who will not actively search for more environmentally friendly proteins. Similarly, previous work by the same authors found that hybrid meat products could be acceptable to many consumers, especially those who are weakly involved, because they may seem more familiar to them [5,8].

While these studies offer initial invaluable findings that could be used to develop more popular hybrid meat products, more research is still needed to understand sensory aspects and specifically consumer attitudes towards those products. Having a better understanding of which factors might have an impact on consumer acceptability would allow the effective formulation and marketing of existing and future hybrid meat products. A more holistic and multidisciplinary approach could offer richer and more nuanced insights into the stance and views of consumers, including a range of perceived

advantages and disadvantages. Consumers' online reviews provide a unique opportunity to do so and allow the researcher to tap into consumers' authentic responses and opinions on dimensions that are relevant to them, but might not have been included and tested in previous research. Because online reviews are essentially texts, they require text analytics derived from linguistics. We explored consumer's attitudes towards hybrid-meat products in online reviews by utilising tools and techniques of corpus linguistics that allowed quantitative identification of the most frequent words and key terms across larger textual data sets. Frequency counts and key terms are useful in that they can highlight the distinctive (salient) words and two-word combinations in a given data set (a corpus of texts), which in turn point to dominant stances and attitudes shared by producers of the texts. The tools and techniques of corpus linguistics were applied to study a corpus of 201 online reviews in order to identify the dominant stances and opinions expressed by consumers who bought and consumed hybrid-meat products.

The aim of this study was therefore to (1) review the presence of hybrid meat products in the UK market, and (2) extract UK online consumer reviews on hybrid meat products and gather preliminary consumer insights utilising tools and techniques of corpus linguistics.
