Short Food Supply Chains in Europe: Scientiﬁc Research Directions

: In the food sector, new conﬁgurations of supply chains, as opposed to global conventional ones, are drawing the attention of researchers and institutions all over the world. These are presented as a panacea for the recovery of rural economies and, in general, of food system sustainability. In this context the short food supply chains (SFSCs) become relevant, as happens in Europe, where strategies and regulations designed on their implementation were adopted. Recognising that scientiﬁc research always plays an important role in guiding institutions’ choices in many ﬁelds, it seems important to focus on how SFSCs are considered in the European academic panorama. Therefore, this contribution presents a study performed on a sample of 108 papers published in journals during the last decade. The ﬁndings concerning the investigated issues and the approaches to analysing SFSC development and effects are reported from both the producer and consumer perspective. The review strongly emphasizes the factors affecting participation in SFSCs. Moreover, it highlights that the positive perception of SFSC sustainability is not based on scientiﬁc evidence. The analysis outlines current research directions and identiﬁes challenges that are still open in order to offer researchers food for thought with a view to developing further future insights. in this case, the papers focused on whether and how certain factors inﬂuence the participation of farmers in SFSCs [7,43,47,


Introduction
Public and private stakeholders in the food sector are showing an increasing interest in short food supply chains (SFSCs). At the European level, the development of shorter supply chains is configured as a key pillar of the "Farm to Fork" strategy for the transition to a more sustainable food system, and in particular for the recovery of rural economies [1]. The European Regulation n.1305/2013 on support for rural development defines SFSC as "a supply chain involving a limited number of economic operators, committed to co-operation, local economic development, and close geographical and social relations between producers, processors and consumers" (art. 2, l. m) [2]. As emerges from this definition, the number of operators and the local scale of implementation are two identifying features of the supply model in European legislation. In the following European Regulation n.807/2014, more clarity is achieved by specifying that there should be no more than one intermediary between producer and consumer [3]. Although this point of view is generally accepted, different declinations of the SFSCs explored by scientific literature have made the boundaries of the concept nebulous. In this regard, the emergence of new intermediaries [4] or organizers and promoters [5,6] or the massive use of e-commerce in response to the current health emergency [7][8][9] cannot be overlooked. Even more vague is the characterization of local product [10,11], which is widely treated by the literature in connection with SFSCs [11][12][13][14]. The difficulty in finding an unambiguous definition lies in the subjectivity of the local connotation: it can vary according to numerous physical parameters, such as population density, accessibility and degree of urbanization but also according to social parameters such as trust and cooperation [15]. However, the main characteristic considered for local product identification appears to be geographical proximity between producer and consumer [10,16,17], a condition not necessarily verified for SFSCs, as in the case of spatially extended interactions [17]. Thus, SFSCs are configured as alternative food networks (AFNs) in which the proximity parameter acquires importance: the local dimension is certainly underlined in opposition to the globalized one typical of conventional food supply chains, but above all, social proximity determines the shortening of the supply model.
SFSCs are currently spreading to various food sectors, especially those dealing with easily perishable foods such as meat, eggs, dairy products, fruit and vegetables. For many years, farmers have replaced local fruit and vegetables production with other more profitable crops to meet market demands, as in northern Italy in the case of the local square pepper replacement with tulip bulbs for the Dutch supply chain [18]. On the one hand, this orientation allowed an increase in productivity and standardization of agricultural products, while on the other hand, it led to a reduction in biodiversity. A return to local products in an SFSC system can therefore stimulate the preservation of the environment and traditional culture as well as expanding local food distribution and creating income for small farms and the territorial context [19]. Small food producers, in fact, have difficulties in accessing larger markets given their reduced production volume and, even in the case of entering one of these, their bargaining power and the relative share of profit would be limited due to lengthening of the supply chain [20]. SFSCs and their outputs therefore represent important tools for rural areas development and for the value redistribution among all stakeholders involved directly and indirectly [21,22]. Among distribution channels, direct sales represent the typical channel of SFSCs [23,24], but with the advent of the internet, e-commerce needs to be considered [25][26][27]. In fact, e-commerce becomes a tool for creating close socio-territorial relationships, characteristic of SFSCs, through the direct and instant contact between producer and consumer-extremely useful for the presentation of food products [28]. In this case, the production site may be very distant from the place where consumers will ask for delivery, thus missing the physical element of geographical proximity.
On the consumer side, a growing preference for SFSCs and their products has been shown too [29,30]. Consumers declare their appreciation for multiple reasons, including the possibility of following a healthy diet, safeguarding the environment, greater transparency and traceability. Despite this, they are still hesitant in buying these products due to their higher prices compared with those of large retailers [31]. Nevertheless, this new demand is driving structural changes in small rural organizations that have created new business methods in order to be more sustainable and innovative [32].
In recent years, several literature reviews addressing single aspects of SFSC have been published. Chiffoleau and Dourian (2020) [33] and Kiss et al. (2019) [34] explored the issue of sustainability by looking at SFSC impacts in environmental, economic and social dimensions. Both contributions underline that the sustainability of this supply model is not undisputed; it highly depends on the specificity of the case analysed and the territorial context. In this regard, analysing the phenomenon in the European context and in particular in France, Kiss et al. (2019) [34] find a certain consensus only regarding the SFSCs' positive impact in the social sphere. The logistics area is addressed in a systematic way only by Paciarotti and Torregiani (2021) [35]. The authors provide an overview of the improvements for SFSCs' sustainability from the logistical point of view and propose several future research paths about distances travelled by consumers and producers, technologies, evaluation methodologies and distribution models. Regarding the latter, it is highlighted that structuring networks on the basis of horizontal and vertical integration among the various actors leads to greater efficiency, and therefore competitiveness [35]. Thomé et al. (2021) [36] carried out an attempt to provide a conceptual framework reflecting the complexity of food supply chain models to overcome the limiting dichotomy between conventional and short chains. The authors created an operating model in order to identify development opportunities on a broader spectrum-a conceptual framework including the various actors and interactions that dynamically cover different types of supply chains simultaneously [36].
In this context, the research presented here aims to offer an overview of the SFSC phenomenon in the European territory. An in-depth study specifically referring to European countries was already published in 2013 by the Joint Research Center (JRC) [16]. The final objective of the report was to collect all information necessary for proposing a possible labelling scheme of local product direct sales. The analysis was therefore implemented to identify the SFSCs' characteristics within local food systems in the first decade of the 2000s. For the present contribution, the focus is instead different, as it is not restricted to the concept of a SFSC as a source of local products; rather, it aims to investigate and clarify the complexity of these alternative distribution forms. The authors' intention is to highlight to what extent and according to which parameters different aspects of SFSCs have been analysed in the academic panorama. The objective is to unpack the scientific literature in order to identify the most discussed issues, the applied evaluation approaches and the findings. Moreover, special attention is paid to the issue of sustainability: how it is perceived, on the one hand, and how it is objectively assessed, on the other. The general purpose is therefore to contribute to the systematisation of SFSCs knowledge through a descriptive framework drawn from the literature. In order to achieve these objectives, a comprehensive systematic literature review was carried out. Starting from specific experiences, the macro purposes and perspectives adopted by scientific research have been retraced; therefore, this contribution adds to previous literature reviews, which focused mainly on a single perspective or aspect such as sustainability [33,34], logistics [35] or the coexistence of different supply models [36]. Attention was also paid to identifying challenges that are still open in order to offer researchers food for thought with a view to developing further future insights. The paper is structured as follows: after this introduction, the definition of the research strategy, the research questions and the paper selection process follow in order. In the third section, the results are presented according to the research questions defined above. Subsequent sections are dedicated to discussion and conclusions; in the last section, the outcomes emerging from the review are summarised.

Literature Review Approach
The literature review was carried out according to the systematic approach proposed by Denyer and Tranfield (2009) [37] which has already been adopted in the field of management and organization studies by several authors, as found in Wong et al. (2012) [38] and Paciarotti and Torreggiani (2021) [35], who conducted systematic reviews in the supply chains area. The approach adopted ensures that rigorous, verifiable and repeatable analysis is performed. The research protocol is based on five steps: (i) research questions formulation; (ii) locating studies; (iii) selection and evaluation of studies; (iv) analysis and synthesis and (v) reporting and using results. Each step is discussed in detail in the following sections.

Research Questions Definition
The state-of-the-art overview and the identification of the most discussed topics about SFSCs in the introduction provided the basis for defining the research questions. In order to guide the investigation of the researchers' contributions to SFSCs literature, two specific questions (S) were refined.
Specific research questions are: • S1: Which themes have been explored and which approaches have been applied to analyse the development and effects of SFSCs? • S2: How does the scientific literature address the issue of sustainability?

Location, Selection and Evaluation of Studies
After the research questions definition, the strategy for selecting the articles was implemented following four phases: (i) databases selection, (ii) contributions extraction, (iii) abstract screening and (iv) full-text screening. For the completion of (ii), (iii) and (iv) phases, eligibility criteria were applied.
Scopus by Elsevier (Amsterdam, The Netherlands) and Web of Science (WoS) by Thomson Reuters (Toronto, ON, Canada) were chosen for the consultation, as they are recognized today as being among the largest databases of abstracts and citations of peerreviewed literature; therefore, they ensure the best coverage for this research. Exploratory investigation was important for the choice of keywords, as it was noted that the research does not refer to univocal words for the short supply chain concept. For this reason, the authors decided to use two different declinations: in addition to the "short food supply chain" keyword, the expression "short supply chain" was used in connection with the term "food". In this manner the authors started from a larger but more representative sample. Thus, the bibliographic search was carried out for all contributions using the following search strings: "short food supply chain" or "short supply chain" and "food". Overall, 484 potentially selectable contributions were identified within the databases, of which 346 were from Scopus, and 138 were from WoS. A filtering process based on language, document type, source type and publication years was then performed on both groups. Only scientific papers written in English language and published in journals from 2012 until September 2021 were selected. The year 2012 was chosen as the lower time limit because it was one year before the publication of the first European regulation [2] which made explicit the role of SFSCs for sustainable development. Therefore, this limit was chosen to include all contributions published after the importance of these models was claimed at the institutional level. In total, the filtering process led to the selection of 329 papers, of which 236 were from Scopus, and 93 were from WoS. After further verification, 73 were removed because they were duplicated.
Subsequently, the 256 remaining papers were submitted to abstract screening in order to select only those in which the SFSCs represented the main focus, whether these were analysed (i) individually, (ii) in context with local food systems or (iii) in contrast with traditional supply chain models. In line with these criteria, the abstracts screening led to the elimination of 79 articles. On the basis of the information extracted in the abstract screening phase, the authors grouped the 177 selected articles according to the geographical area in which the research exercise was carried out to obtain a summary picture of the SFSCs territorial distribution. The contributions focused on the SFSC models in Europe, which represented more than 78% of the total; the remaining were divided between the other continents: about 10% American continent, 6% Asia, 1-2% Africa and 3% Oceania. Therefore, before proceeding to full text screening, the authors further narrowed the sample based on geographical distribution data. Indeed, the scope of the review being to investigate the characteristics and dynamics of SFSCs in the European territory justified the elimination of papers referring to other continents. In any case, the data on the territorial distribution were useful, as they were a testament to a high level of interest in the context investigated by this study. Finally, as a consequence of the application of the geographical criterion, the articles selected to be subjected to full-text screening decreased to 139.
The full text screening was conducted to further verify the existence of the aforementioned eligibility criteria. The implementation of the search strategy eventually led to the selection of 108 articles. Figure 1 shows the articles selection process. Sustainability 2022, 14, x FOR PEER REVIEW 6 of 22

Analysis and Synthesis of Studies Characteristics
The selected articles for systematic literature review are listed in Table 1 in descending order by publication year. For each of the articles, the reference, geographical area of case study implementation and source are indicated. Figure 2 shows how, starting from 2012, scientific interest in the subject has tended to increase. The increase in the number of publications in the second part of the time period was not only driven by the European documents' [1-3] diffusion but also by the implementation of the 'Short supply chain Knowledge and Innovation Network' (SKIN) project [14,[39][40][41][42], by the progressive integration of the 'Links between the rural economy and development actions' (LEADER) programme in European rural policy [5] and by the interest in SFSC diffusion and transformation during the health emergency period [7][8][9]. Between 2020 and 2021, there was a decrease (Figure 2), probably because the upper limit for the bibliographic search was set at September 2021. As regards the sources, there was a wide variability: a total of 57 journals were counted, but only 5 published more than 3 selected articles. Among the most relevant was Sustainability, followed by Studies in Agricultural Economics and Agricultural and Food Economics. While Sustainability is a cross-disciplinary journal that deals with the sustainability spheres, a macro-topic called to attention for the SFSCs policy, the other two are focused more on the socio-economic spheres of the agricultural sector and on the organization and management of agri-food chains. In addition to the source, the authors considered it important to specify the geographical area of the case studies' implementation (Table 1, second column) in as much as the SFSCs represent a territorial phenomenon that is highly influenced by cultural, physical and economic factors that can vary greatly according to the analysed context. In total, 29 countries were involved, all belonging to the European area, with the exception of Mexico, Egypt, Brazil and Vietnam, which were automatically included, as they were analysed in conjunction with the countries of interest for the review. Figure 3 shows the most frequently cited countries: 45 case studies were implemented in Italy, followed by France and Hungary, both considered in 21 articles.

Analysis and Synthesis of Studies Characteristics
The selected articles for systematic literature review are listed in Table 1 in descending order by publication year. For each of the articles, the reference, geographical area of case study implementation and source are indicated. Figure 2 shows how, starting from 2012, scientific interest in the subject has tended to increase. The increase in the number of publications in the second part of the time period was not only driven by the European documents' [1-3] diffusion but also by the implementation of the 'Short supply chain Knowledge and Innovation Network' (SKIN) project [14,[39][40][41][42], by the progressive integration of the 'Links between the rural economy and development actions' (LEADER) programme in European rural policy [5] and by the interest in SFSC diffusion and transformation during the health emergency period [7][8][9]. Between 2020 and 2021, there was a decrease (Figure 2), probably because the upper limit for the bibliographic search was set at September 2021. As regards the sources, there was a wide variability: a total of 57 journals were counted, but only 5 published more than 3 selected articles. Among the most relevant was Sustainability, followed by Studies in Agricultural Economics and Agricultural and Food Economics. While Sustainability is a cross-disciplinary journal that deals with the sustainability spheres, a macro-topic called to attention for the SFSCs policy, the other two are focused more on the socio-economic spheres of the agricultural sector and on the organization and management of agri-food chains. In addition to the source, the authors considered it important to specify the geographical area of the case studies' implementation (Table 1, second column) in as much as the SFSCs represent a territorial phenomenon that is highly influenced by cultural, physical and economic factors that can vary greatly according to the analysed context. In total, 29 countries were involved, all belonging to the European area, with the exception of Mexico, Egypt, Brazil and Vietnam, which were automatically included, as they were analysed in conjunction with the countries of interest for the review. Figure 3 shows the most frequently cited countries: 45 case studies were implemented in Italy, followed by France and Hungary, both considered in 21 articles.  [61] ESP, Andalucía Land Barska and Wojciechowska-Solis (2020) [12] POL Sustainability Jarzebowski et al. (2020) [14] SKIN project countries 1 Sustainability Lioutas and Charatsari (2020) [62] GRC, Crete island Land Use Policy Tundys and Wiśniewski (2020) [63] POL, West Pomeranian Province Appl. Sci. Raftowicz et al. (2020) [64] POL, Barycz Valley, Wrocław Sustainability Rucabado-Palomar and Cuéllar-Padilla (2020) [65] ESP, Malaga Province Renew. Agric. Food Syst. Koutsou and Sergaki (2020) [66] GRC Br. Food J. Armesto-López et al. (2020) [67] ESP, Barcelona WIT Trans. Ecol. Environ. Pato (2020) [6] PRT

Results
With the new European rural development policy, the SFSC structuration ceases to be a simple tool for supporting marginal and non-competitive agriculture and becomes important for achieving the general objectives of rural development and for maintaining the vitality of rural areas [135,136]. In this context of growing enhancement of new supply chain models, the aim of this paper was to provide an overview of the SFSC phenomenon in the European territory, in order to identify its characteristic features and find out which of these could be further investigated by the scientific community. The analysis of the selected papers (Table 1) was directed to answer the specific questions; the results obtained for each of these are presented in the following sections.
3.1. S1: Which Themes Have Been Explored and Which Approaches Have Been Applied to Analyse the Development and Effects of SFSCs?
Farmers and consumers are the main stakeholders acting within SFSCs. In order to identify the most important themes and the approaches applied, the authors considered it appropriate to distinguish the perspective adopted in the contributions and then present the results according to these.

Farmers
The papers that focused on the farmer's point of view, in some cases accompanying it with that of other SFSC participants, were 46 in total. These included a few observational studies aimed at providing structural characteristics of farms [39,67,128] and descriptions of the sociodemographic characteristics of participants [83], and another broader part of contributions focused more specifically on the relationship between the involvement of farmers in SFSCs and factors related to farming system characteristics and the individual sphere of the producers. Generally, involvement in SFSCs was detected on the basis of the proximity between producer and consumer and thus in terms of the amount of food sold through the different types of short chains. This involvement may in turn be influenced by certain elements related to the farmer dimension. Overall, among these elements, those describing the performance of farming systems, such as economic, technical and environmental key indicators, and those relating to the individual sphere of the farmers, such as competencies, intentions, motivations and perceptions, were considered in the reviewed literature. Therefore, based on how the relationship between participation in SFSCs and the farmer dimension was analysed, two research strands representing two sides of the same coin were identified ( Figure 4). The first strand is represented by studies [7,41,49,52,56,61,82,110,124,128] highlighting whether and to what extent the orientation towards SFSCs influences elements relating to the farmer dimension. On the other side, another larger sub-group [47,54,56,61,64,65,69,75,76,80,86,90,94,95,97,98,101,102,104,108,113,115,118] investigated the same relationship but in the opposite direction: these authors focused on identifying whether and how certain farmer characteristics influence the choice by farmers to participate in SFSCs and whether they boost the development of these supply chain models. Figure 4 summarises the proposed framework by indicating, on the arrows identifying the type and direction of the relationship, the references of the papers that discussed it.
Within the first strand, greater attention was paid to the trend of some key indicators relating to the economic and managerial sphere of the farms. According to Filippini et al. (2016) [112], the market orientation of peri-urban agricultural systems, defined as the conscious market destination chosen by farmers, is a driver of farm management and land use intensity; but on the other hand, the analysis model used does not enable the indication of which type of supply chain is the most impactful in this sense. From their contribution emerges, however, that SFSCs can have as much of an agriculture-intensive performance as conventional ones. A different idea is supported by Gaviglio et al. (2021) [43], who only consider technical efficiency and affirm that it is not affected by orientation towards SFSCs. Rover et al. (2020) [58] discuss the agrobiodiversity factor. In this case, the results obtained analysing peri-urban farming systems show a significant and positive correlation between the wealth index of crops and the share of sales through alternative food networks. Other contributions focused on economic indicators as profit [7,63,126,130] and value added [51,84]. It emerged that market channel and product category diversification represent a winning strategy for small and medium farms since integrating direct selling with conventional distribution leads to greater economic benefits [7,61,124,128] Lastly, to complete the picture relating to the issues addressed from the point of view of producers, the topic of sustainability is discussed. Contributions dealing with this issue generally aim at investigating SFSC sustainability through qualitative and quantitative methodologies considering stakeholder perceptions or representative indicators for every sustainability dimension. Some authors [73,78,100,123] propose a framework for assessing the sustainability of different supply chains starting from data collected only among farmers, while others [77,81] analyse the perceptions not only of farmers but also of consumers and retailers as well. The way this issue has been addressed in the SFSC literature is discussed more fully in Section 3.2.

Consumers
Fewer papers take into account only the consumers' point of view. Moreover, comparing with the results on farmers, a greater homogeneity of opinions is observed.
Most of the contributions carried out exploratory analyses to identify the socio-economic characteristics, attitudes and motivations of consumers participating in different types of SFSCs [11,29,44,53,66,74,83,85,97,105,120,127], and some of them added cluster analysis in order to define target consumer groups [97,105].
Regardless of context, in several contributions a significant correlation was found between level of education and the choice to purchase food through a SFSC. Of course, other socio-economic variables such as gender, income and age were also detected in the consumer samples of the various studies, but what stood out most during the full text screening was the widespread agreement on the finding that the consumers involved in SFSCs generally have a high level of education [11,53,66,74,83,85,105]. Furthermore, the reviewed scientific literature focused on the importance of the role played by attitudes and motivations: in this case, differences were noted as to which ones have greater effect, depending on the SFSC type and territorial context analysed. A singular point of view is provided by a study on the positive effect of ethnocentric attitudes on SFSC development in Poland [68]. However, in general, environment-friendly attitudes and attention to quality, freshness and healthiness have been identified as determinants guiding these consumption choices [ [98], cooperation is not a significant variable: education and investment-oriented behaviour better explain the preference for this alternative market in Hungary. Even an analysis of Croatian farmers [90] partially reported the same conclusions: education and willingness to invest through European funds were revealed as determinants, together with other farm structural characteristics such as size and type. On the sustainability aspect, a theoretical framework based on the combination of transformation, sensing and sizing capabilities to optimize the performance of local food systems is proposed by Gruchmann et al. (2019) [76]. Others [82,101,104,113] are positioned even further upstream, as they highlight in particular the psychological aspect influencing intentions and decisions of farmers. In one case, the intention of farmers to scale-up SFSC business [104] and in another case their intention to conduct direct selling [101] were evaluated through the theory of planned behaviour (TPB): in both con-tributions the conclusions underline that personal attitudes are the main driver for SFSC development. Giacomarra et al. (2019) [82] also use the TPB to evaluate the intention of SFSC farmers to shift from carbon to electric mobility. The results show that producers with stronger intention have a higher environmental concern, and it is argued that the social and cultural context can have a great impact on these innovation proposals. Another interesting insight into farmer behaviours was provided by the application of conventions theory (CT) [49] in order to evaluate differences and similarities among SFSC actors' perceptions: a complete picture of the forces driving their behaviours was described, and a common agreement was found regarding the importance of product quality and reputation. Farmers' use of smart technologies is remarkable and constitutes an emerging topic [7,39,62,95]; digitalization in SFSCs appears to affect perceptions negatively because it is seen as a conventionalization process that could break the direct connection between consumer and farmer [62]. Generally speaking, motivations determining involvement in SFSCs can be of different nature: starting from a social, economic or cultural reason, it is possible to identify corresponding farmer profiles [97]. Some authors report producers' interest in meeting consumers' needs [108] and forging a loyalty relation [56] as the main motivation underlying participation. Nevertheless, a research study conducted in Hungary highlighted that farmers lack in-depth knowledge of their customers' needs, and on top of this, they overrate their own ability to satisfy them [119]. However, even if the reasons and motivations mentioned in the literature are mainly connected to the social dimension of the individual, the economic one is relevant too. Benefits deriving from the interaction based on mutual respect and recognition are significant, but contextually, it was noted that the intention to grab an economic opportunity and escape conventional markets in which producers would suffer from competition [108,119].
Other contributions focus on observing under what terms the structural characteristics of a farming system can affect the development of SFSCs [47,86,115,118]. Typically the presence of small farms, their distribution and the type of food offered [115,118], and also the orientation towards certification schemes as registered for the Lombardy territory [86], are considered factors boosting the diffusion of SFSCs.
Lastly, to complete the picture relating to the issues addressed from the point of view of producers, the topic of sustainability is discussed. Contributions dealing with this issue generally aim at investigating SFSC sustainability through qualitative and quantitative methodologies considering stakeholder perceptions or representative indicators for every sustainability dimension. Some authors [73,78,100,123] propose a framework for assessing the sustainability of different supply chains starting from data collected only among farmers, while others [77,81] analyse the perceptions not only of farmers but also of consumers and retailers as well. The way this issue has been addressed in the SFSC literature is discussed more fully in Section 3.2.

Consumers
Fewer papers take into account only the consumers' point of view. Moreover, comparing with the results on farmers, a greater homogeneity of opinions is observed.
Most of the contributions carried out exploratory analyses to identify the socioeconomic characteristics, attitudes and motivations of consumers participating in different types of SFSCs [11,29,44,53,66,74,83,85,97,105,120,127], and some of them added cluster analysis in order to define target consumer groups [97,105].
Regardless of context, in several contributions a significant correlation was found between level of education and the choice to purchase food through a SFSC. Of course, other socio-economic variables such as gender, income and age were also detected in the consumer samples of the various studies, but what stood out most during the full text screening was the widespread agreement on the finding that the consumers involved in SFSCs generally have a high level of education [11,53,66,74,83,85,105]. Furthermore, the reviewed scientific literature focused on the importance of the role played by attitudes and motivations: in this case, differences were noted as to which ones have greater effect, depending on the SFSC type and territorial context analysed. A singular point of view is provided by a study on the positive effect of ethnocentric attitudes on SFSC development in Poland [68]. However, in general, environment-friendly attitudes and attention to quality, freshness and healthiness have been identified as determinants guiding these consumption choices [11,29,44,49,53,74,81,83,85,97,120,125]. The contribution of Giampietri et al. (2015) [120] was the only one among the reviewed papers to use the TPB in order to investigate these influencing factors, while Migliore et al. (2015) [125] investigated the effects of quality conventions using a CT framework. In this case it is emphasized that the quality definition process is guided by informal criteria concerning localism, solidarity and trust norms. The predictive role of attitudes was verified by Cicia et al. (2021) [44] and Cicatiello (2020) [53] using a regression model. According to Cicatiello (2020) [53], who addressed the issue on the quantity purchased from different types of SFSCs, the most significant factor is the pursuit of environmental sustainability. Cicia et al. (2021) [44] also found that the frequency of purchases at farmer markets is positively related to an environmental attitude which is in turn positively influenced by values of benevolence and universalism. These results reconfirm what Lombardi et al. (2015) [117] stated about the consumer value system through a comparative study among participants and nonparticipants in solidarity purchasing groups (SPGs). The participants are interested in building strong social relationships with other SPG participants with the aim of sustaining the well-being of the community [117]. The solidarity motivations are more relevant than those related to personal satisfaction also according to Koutsou and Sergaki (2019) [66]. In contrast, by investigating the SPGs in the metropolitan area of Milan, Baldi et al. (2019) [74] pointed out that food safety and healthiness prevailed over altruistic features linked to the social dimension. Similar results were obtained from a research study in the Hungarian territory for the same type of alternative supply chain; also in this case, personal interests, such as obtaining safe, fresh and reliable food, prevail over attention to the local economy and the environment [85]. These reasons are supported by the scientific demonstration that the shorter length of the chain promotes sustainable diets [71] and has a positive effect on consumers' health [72]. In this regard, the contribution by Santulli et al. (2019) [72] on the risk of metabolic syndrome onset emerges among the reviewed papers.
Another theme taken into consideration is the process of building trust between consumer and farmer [41,46,81,99]. Oñederra-Aramendi et al. (2018) [97] and Delibas (2021) [46] emphasize that trust is not supported by certification requirements but by a close, informal and long-term relationship with the farmer. This relationship acts as a guarantee of quality by carrying a system of physical and symbolic values. The extent to which trust influences consumer behaviour has been instead explored by Giampietri et al. (2018) [99], again using the TPB. According to the extended model employed, this study affirms the indirect positive effect of the trust component on purchase behaviour in SFSCs.
A recently emerging topic concerns the impact of the COVID-19 pandemic on consumer behaviour. The consequences of the state of emergency on the various categories of consumers, as well as on the frequency and methods of purchase in SFSCs, were analysed [8,9]. Two studies conducted in Romania-one for dairy products [8], the other for fresh vegetables [9]-came to slightly different conclusions regarding purchasing preferences. Brumă et al. (2021) [8] found a positive change only in the future reaction of consumers, as they express a greater propensity to turn to SFSCs compared with the pre-pandemic situation, while Butu et al. (2020) [9] register a change starting from the emergency phase. In this case, the percentage of consumers who declared that they bought vegetables directly from producers was 12% in the pre-COVID-19 phase and 60% in the subsequent crisis phase, and 81% also intend to buy at the end of the emergency. On the other hand, both studies [8,9] share the fact that the health crisis has triggered and accelerated the digital transition of SFSCs. However, even before the COVID-19 crisis, discussions about "smart SFSCs" [62] had begun. Many consumers sought out social media channels and company websites to obtain transparent information on farms, products and delivery conditions. Among these, young consumers seemed most likely to use digital channels for food purchases [12,70]. Although it is believed that information and communication technologies (ICT) can act as facilitators in consumer communities [87], it was noted that the inclusion of new technologies and therefore digital transformation is not positively perceived by participants in the SFSCs [62,70,93]. According to consumer opinions, digitalisation undermines the typical characteristics that have distinguished alternative supply chains from conventional ones [62]: the distance among participants increases and the elements of trust and familiarity are lacking [70,93]. In addition to this, price, availability and shelf time are considered the main barriers to the development of e-commerce [12].

S2: How Does the Scientific Literature Address the Issue of Sustainability?
In the last 20 years, SFSCs have been re-experienced and have been considered innovative approaches for the sustainable development of rural communities [8] and farming systems [14], representing a less impactful alternative to the global chain [99]. From the beginning, scientists, as well as practitioners, have identified as distinguishing characteristics of a SFSC its (i) economic viability, (ii) environmental sustainability and (iii) social interaction [133]. The detachment from all intermediate stakeholders of a conventional supply chain is closely related to the consolidation of the three above-mentioned characteristics, as they permit fair prices that are not disproportionate to the food real value, allow for reduction in the environmental impact of food, and establish new social relations [4]. According to Poponi et al. (2021) [47], bio-districts are a SFSC concept that affects all sustainability aspects. They sustain landscapes, biodiversity and resources of the territories and are encouraged by a request for varied sustainable products. Such districts allow companies to better manage autonomously crucial aspects linked to their economic sustainability such as supplies, marketing, customer relations and selling price decisions. Moreover, the social benefits are linked to the possibility of enhancing the farmer-consumer relationship, the creation of jobs, which implies the participation of young people, and a culture of sustainability [47].
On the consumer side, there is evidence of a growing demand for products obtained from SFSCs, supported by concern about social, economic and environmental sustainability aspects [51]. Consumers believe that food provided by SFSCs tends to have higher quality characteristics, to be tastier, healthier, fresher and more authentic, and also, it contributes to enhancing economic advantages, avoiding negative externalities and building welfare and social solidarity [4,6,29,65,117,122]. However, it has been pointed out that this attitude is not based on scientific considerations: the empirical evidence of the SFSCs' positive impact is very limited; therefore, consumers base their preferences and purchasing decisions more on concepts and beliefs than on proven consequences [70]. In this regard, [52,81] highlighted that the results about advantages for sustainability are specific to the case study under consideration and cannot be generalized. Mancini et al. (2019) [81] stated that producers' practices have generated positive externalities without however neglecting the greater environmental impact due to consumers' trips to reach the point of sale. They still resolve this hot spot by interpreting it as an opportunity cost for the remaining sustainability dimensions. The same criticality about the distance to travel in the case of on-farm selling is stressed by [52,126].
Despite this evidence, the main statement related to the environmental dimension of sustainability was that the geographical proximity typical of SFSCs allows for reduction in environmental costs associated with food distribution [5,57,63]. In any case, part of scientific literature highlights that, in addition to ever-changing food miles, the just-in-time delivery of food has to be carefully managed because it could lead to a considerable increase in GHG emissions because of the smaller shipment sizes of products [42,57,103] and the transportation mode [57,91]. Regarding the latter, [45,82] discuss the introduction of electric freight vehicles as a more sustainable option for the food transport sector. Other aspects emerge in the reviewed papers: the environmental sustainability related to SFSCs is also linked to the farms' characteristics and strategies [108], to the use of natural resources such as water and land, which may be considered critical inputs of the agricultural activity [43], to animal welfare practices and biodiversity [29,66], to the minimization of disposable packaging [109], to the absence of chemical fertilizers or pesticides [76] and in general to the more eco-friendly production methods connected with organic farming [100].
As regards the economic dimension of sustainability, several factors are considered, especially concerning producers. The participation in SFSCs guarantees farmers an increased production value and therefore a greater share of value added [57,100,106,119,130]-and indirectly, a reduction in operating costs with the acquisition of greater margin and operating income [100]. Some contributions [14,39,57,100,106,119,130] identify the key to this economic improvement mainly in the elimination of intermediaries: the lower costs of intermediation consequently improve their income. On the other side, it seems that the capacities of SFSCs to support long-term economic sustainability have to be proved [91,102,108]. Similarly, the contribution of Gaviglio et al. (2021) [43] concludes that diversification through SFSCs does not significantly improve the economic performance of farmers in terms of technical efficiency. From a broader point of view, other factors are mentioned relating to the capacity of SFSCs to boost employment, human and social capital investments, changes in the economic system, transparency and synergies between stakeholders [14,66].
Moreover, the social sustainability of SFSCs rises up among the studies taken into consideration. These supply chain models are undoubtedly characterized by social benefits. Close cooperation and geographical and social relations between farmers and consumers are reflected in a strengthening of dialogue and trust [39,57,63,77,108], while encouraging the progress of local communities [12]. In order to develop, this form of cooperation must in any case meet the socio-economic features of the territory; in fact, low interest in SFSCs was found among farmers operating in a centrally planned economy [118]. It was observed that the closer relationship among stakeholders has spillover effects with regard to the redistribution of value and the formation of more resilient market governance structures [87]. Another effect mentioned is the forging of a rural area's cultural identity [39,84]. The inhibition of information asymmetry is one of the most important consequences of this social proximity [120]: consumers can benefit from a more conscious understanding of food related to the raw materials' origin, production process, waste, ethical themes, health and safety [44,91]. Regarding the latter, contradictory points of view have emerged in the reviewed literature. Corsi and Mazzocchi (2019) [86] affirmed that a healthier lifestyle is provided by SFSCs only for richer and more aware consumers. Instead, Bimbo et al. (2015) [124] statistically proved that consumers benefit from SFSCs, as a higher presence of farmer markets is associated with a reduction in individuals' obesity rates. Similarly, Santulli et al. (2019) [72] consider the length of the supply chain, and they suggest that it might affect cardiovascular risk, but in order to verify this hypothesis, it is crucial to compare populations that present similar dietary patterns. On the other side, SWOT and microbiological analyses performed on dairy products have shown that SFSCs are more vulnerable [121]: in this regard an obstacle for small producers is the cost to meet the same safety requirements existing for a long supply chain [80].
An attempt to provide a quantitative measure for each of the sustainability dimensions of different types of supply chain was addressed by Malak-Rawlikowska et al. (2019) [78], who proposed a set of indicators: six extracted from literature and three socio-economic indicators specifically studied for the specific case. The results achieved do not allow them to state that SFSCs are more sustainable than long ones: certainly for the producers there are generally economic benefits, but more contrasting results from the other indicators are obtained for the further dimensions [78]. A qualitative analysis was instead carried out by Vittersø et al. (2019) [77] to investigate the perceptions of SFSC actors regarding a SFSC's contribution to the aspects of sustainability. In this case, the authors observed a common positive perception only about the social dimensions.

Discussion
The SFSCs model is praised as an alternative to global food production and distribution. This supply model is developing according to different configurations as a response to dissatisfaction with a mass industrial-type system that has disappointed the expectations of consumers and producers. On this basis the scientific literature on the subject has taken root. Thus, ever since the phenomenon was recognised, it has almost automatically been attributed all those economic, environmental and social benefits and values that are no longer supported by global conventional chains. The review of scientific production showed that over time more attention was paid to avoidance of falling into the trap of "the shorter the better". A more critical view has been adopted. Based on the previous section, the discussion of results is carried out with the final aim of suggesting further developments in scientific production.
SFSCs can be very different and can exist at different levels of growth. The supply model investigated across the various countries of the European territory takes up different forms and meanings depending on the territorial, cultural and economic contexts in which it is located [48,69], and such heterogeneity is reconfirmed by this review. For this reason, it is difficult to carry out comparisons and generalize results. In order to better frame the various initiatives, the authors provide indications on the geographical distribution of the case studies (Table 1). Popp et al. (2018) [88] stressed the difference between the richer EU countries and the new EU members, in which the presence of multinational companies is strong and hinders the development of alternative models. In former years, SFSCs tried to increase both competitiveness in the market and profits, but the need for proper management arises in order not to be incorporated into traditional mechanisms, which can be accomplished by building transparent relationships not only between farmers and consumers but also with other actors such as promoters, public organizations [97,118,133] and new intermediaries [4].
In the revised panorama, scientific discussion has focused more on investigating a farmer's profile and how it fits into the SFSC models. Some of the contributions explored the effects on the economic and managerial sphere of farmer systems induced by the adoption of this market orientation. It is pointed out that farmers obtain economic advantages, i.e., fair and stable prices, autonomy and immediate payment. In any case, in the long term, the adoption of an exclusively short market orientation does not pay. Several contributions underline that diversification brings greater economic benefits. Furthermore, specific skills are required to achieve success in alternative supply models. Farms will need to rethink business models, working on strategic and operational decisions. Therefore, training programs are needed to increase skills, especially in product promotion and marketing [54,65,113].
A larger part of the scientific literature focuses on factors affecting participation in SFSCs. Among actors' socio-economic characteristics, education is in most cases counted as the most significant for both consumer and producer involvement. Regarding attitudes and motivations driving behaviours, few authors resorted to a more solid theoretical background; they mostly referred to the TPB or CT. In general, greater importance was given to the reasons connected with the social and environmental dimension, leaving in the shadow considerations of a more economic nature. However, the studies on motivations enable a long-term vision of how short supply chains will develop in Europe. As pointed out by Delicato et al. (2019) [41] for consumption choices, the determinants guiding the involvement in SFSCs are many and changeable over time: it is no longer just a question of "local": factors such as health and economic convenience are gaining more importance. Farmers of the SFSCs have to be very clear and honest about the value proposition of their specific supply chain, as it is very difficult to prove that it is in every way better than the conventional ones. In some cases it is not only difficult but also not feasible, as mentioned for the case reported by Verraes et al. (2015) [121] relating to the issue of food safety.
During the revision process, the concept of multidimensional sustainability has arisen in an explicit or implicit manner according to the purpose of the specific paper. In the literature, the various SFSCs may be considered in a nuanced way by stakeholders, as they may have a different perception of sustainability aspects [77]. In any case, as stated by Aubry and Kebir (2013) [131], stakeholders and scholars have a quite high expectation towards all sustainability dimensions of SFSCs. It is therefore important to better evaluate three sustainability dimensions, and it would be necessary for scholars and public authorities to agree on the identification and use of common indicators allowing comparison data. While the benefits for the social and environmental dimensions of alternative models were considered the most relevant, especially for the part of the literature focused on the consumer perspective, the sustainability indicators calculated by Malak-Rawlikowska et al. (2019) [78] for these same dimensions and for different types of SFSCs reported conflicting results.

Conclusions
The process of reviewing the scientific literature on SFSCs in Europe has been useful for describing the current state of the art and therefore for outlining possible paths for further research. Improvement opportunities for the SFSC system unfold in various directions and are in any case changing over time, as the COVID-19 crisis teaches.
First of all, the overview offered by the mapping of SFSC cases in Europe provides an informative basis for further analysis; it could be useful to observe the geographical distribution of the studied initiatives and to identify by which territorial, cultural and political factors their development pattern might be influenced. However, it must be taken into account that the majority of these articles analyse SFSCs from the farmers' point of view. The consumers' point of view is less considered and even smaller is the number of contributions focusing on promoters and intermediaries-a category of stakeholders nevertheless present within the framework of alternative models. Consumer and farmer motivations emerge among the more in-depth themes: their knowledge could certainly improve the planning and implementation of SFSC strategies. However, the aspect of creating an alternative to globalized supply chains led to more emphasis on intrinsic values. In this context, the social and environmental sphere attracts more attention than the economic one. Instead of continuing in a scientific discussion marked by contrast, the use of frameworks based on coexistence with long supply chains would open new solutions, even if SFSCs are not in themselves sustainable. Actors' perceptions of the sustainability of alternative models is not based on scientific evaluations. Appropriate assessment tools should be used for each specific case before declaring the connected benefits. Finally, the issue of SFSC digital transition does not seem to be perceived positively by participants. The importance it acquired with the outbreak of the pandemic crisis will continue to grow. The extent to which digitalisation and ICT will influence the relationships governing SFSCs can be investigated. This factor, together with the recognition of the new supply models by the institutions of the EU and its member states, will inevitably lead to changes in the practices of spontaneous decentralized cooperation.
These considerations, flowing from the outlined results and discussion, are key points that will hopefully be useful for researchers who seek to develop further insights in future. The paper does however have some limitations. The data were collected using specific paper selection criteria, which might show some flaws, e.g., the choice to limit the search to two databases. In this case, WoS and Scopus are the most popular scientific repositories with multidisciplinary products. This choice allowed access to contributions and papers belonging only to the peer-reviewed literature, excluding grey literature and reducing the basis of selected papers. Moreover, some aspects related to the study of content are not explored and investigated-e.g., the analysis of the applied methods. In this sense, the limitations of the paper are useful suggestions for the design of new research on the SFSC movement.