# Addressing Sustainability within Public Procurement of Food: A Systematic Literature Review
## 2 Methodology  
To explore how sustainability is framed in the context of public procurement of food and food services in the scientific literature, a systematic literature review was conducted. The approach was employed due to its applicability to find articles of relevance and encompassing a broad range of disciplines. It allows the application of exclusion criteria to explore a range of scientific literature from different disciplines [25]. Similar methods have been applied to explore the research field of sustainable procurement, organic food in public kitchens, and environmental impacts in specific sectors [26; 27; 28; 29]. The first step included identifying relevant peer-reviewed scientific literature between the years 2000 and 2020. The Scopus (www.scopus.com), GreenFile (www.gebsc.com) and Web of Science (www.webofknowledge.com) databases were employed for the searches, between 17 June 2019 and 18 December 2020, as they are established search engines and ensure coverage of a large number of publishers and journals across disciplines. The development of the search string was done iteratively to avoid limiting the results yet avoiding articles off-topic. The search string was divided into four blocks, including terms identifying public, procurement, sustainability, and food. Furthermore, the search was limited to journal articles written in English. For terms which could include different variations of words, an \"*\" symbol was used. For example, the term'sustainab*\" was used to highlight variants of words such as sustainable, sustainability, etc. The final search string employed was as follows:  
_(TITLE-ABS-KEY (public OR government OR \"public sector\") AND TITLE-ABS-KEY (procurement OR tendering OR contracting OR purchasing) AND TITLE-ABS-KEY (sustainab*) AND TITLE-ABS-KEY (food OR catering OR grocer* OR eatables OR feeding*)) AND DOCTYPE (ar) AND PUBYEAR > 1999 AND (LIMIT-TO (LANGUAGE, \"English\"))_  
From the different search engines, a total of 368 articles were obtained. Upon reviewing the references in the collected articles, an additional 23 articles were added to the search upon reviewing the cited studies in the collected literature, giving a total of 391 articles. After removing duplicates, only 290 articles remained, where 19 articles were not accessible through the databases or provided on request and thus excluded. Thereafter, 271 articles were reviewed based on titles, keywords, and abstracts. Only articles specifically addressing public procurement of food and sustainability were selected, whereby articles covering private consumption and shopping as well as articles not addressing sustainability were excluded. In total, 103 articles remained for a more thorough review and analysis; see an overview of this process in Figure 1.  
Once the scientific articles were selected, content analysis was performed as the first step of interpreting findings from the collected literature. Content analysis is an efficient approach to search for and analyze phenomena that cannot be observed directly, including themes, words, and concepts within texts to understand their presence, relationships, and meaning [30; 31]. In this article, we used content analysis to understand how sustainable food procurement is framed in the scientific literature. It included a descriptive content analysis to outline (1) the objectives of the studies, (2) what objects (e.g., specific food products, packaging, or technology) were studied, (3) what methods were used for study design and data collection, (4) geographical coverage, and (5) identifying focus words employed in the context of sustainability, e.g., local, organic and waste. This gave a general overview and understanding of sustainable food procurement literature and served as a background for further analysis. The content analysis also involved screening the articles to identify focus words, i.e., words used to address different sustainability aspects of food production and procurement. The occurrence of focus words was then analyzed.