Table 1. Characterization of studies regarding biodiverse food plants in Caatinga biome.

Study number	Data on publication (authors, year and journal)	Setting	Objective	Design	Participants	Outcomes investigated	Outcomes measurement method	Outcomes	Quality
1	Almeida et al., 2016 (34) Food chemistry	Mossoró, RN, Brazil	To evaluate the bioactive compounds and the antioxidant potential of the fruit of Ximenia americana L.	Randomized experimental study	N/A	Bioactive compounds and antioxidant activity—flavonoids, anthocyanins, carotenoids, vitamin C	Chemical composition analysis of fruits harvested directly from wild plants	Fruits are a potential source of antioxidants, with possible applications in pharmacology, medicine and nutrition	Moderate
2	Carvalho et. al., 2011 (24) Journal of Food Composition and Analysis	Floresta Nacional do Araripe, CE, Brazil	To investigate the food potential of 14 wild legumes from the Caatinga	Randomized experimental study	N/A	Energy, macronutrients, micronutrients and presence of antinutrients—lecithin, trypsin inhibitor, urease–and toxic substances	Analysis of chemical composition of ripe wild seeds collected in dry season	Seeds have nutritional relief equal to or greater than those found in conventional legumes such as beans and soybeans	Strong
3	Cavalcanti; Bora; Carvajal, 2009 (35) Cienc. e Tec. de Alimentos	Santa Luzia, PB, Brazil	To characterize functional properties of the protein isolate of Cnidoscolus quercifolius Pohl almonds	Randomized experimental study	N/A	Macronutrients and functional properties (absorption capacity, emulsification and solubility) of the two varieties of the plant	Analysis of chemical composition of ground almonds	High lipid and protein content. Potential for nutritional applications. The thornless variety showed better water and oil absorption capacity	Moderate
4	Cruz et al., 2014 (25) Journal of Ethnobiology and Ethnomedicine	Altinho, PE, Brazil	To analyze participants' perceptions of native edible plants and relate to socioeconomic factors	Ethnobotanical, observational, cross-sectional study	39 people,> 18 years old, living in one Caatinga rural community	Relationship between the perception of food plants with their use (number of items used) and socioeconomic factors (age, gender, income and occupation)	Semi-structured interviews	Flavor was the positive perception most associated with use; cultural acceptance, negative. Perceptions directly related to age and income	Strong
5	Cruz; Peroni; Albuquerque, 2013 (26) Journal of Ethnobiology and Ethnomedicine	Altinho, PE, Brazil	To relate knowledge, use and management of wild edible plants and socioeconomic factors	Ethnobotanical, observational, cross-sectional study	39 people,> 18 years old, living in one Caatinga rural community	Relationship between knowledge, use, and management (number of items known, consumed, preparations) with socioeconomic factors (age, gender, income, and occupation)	Semi-structured interviews	Knowledge is related to age, but not to occupation and uses. Association between age and use may indicate abandonment of the resource	Strong
6	Nascimento et al., 2011 (36) Food Research International	Altinho, PE, Brazil	To determine nutritional composition of native Caatinga species	Randomized experimental study	N/A	Energy, macronutrients and bioactive compounds—anthocyanins, flavonoids and carotenoids	Analysis of chemical composition of plants, ripe fruits	Plants with high nutritional potential. The study points out plants of interest for future research on bioactive compounds (e.g., Sideroxylon obtusifolium (Roem. & Schult.) T.D.Penn.	Strong
7	Nascimento et.al., 2012 (38) Economic Botany	Altinho, PE, Brazil	Collect ethnobotanical and nutritional data on famine foods	Mixed methods. Phase 1: Ethnobotanical, observational, cross-sectional study. Phase 2: Randomized experimental study	68 people,> 18 years old, living in two Caatinga rural communities	Phase 1: Relationship between knowledge and socioeconomic factors. Phase 2: Energy, macronutrients and bioactive compounds from the seven main species	Free list and semi-structured interview	There is a difference in knowledge between communities. The data demonstrate the nutritional potential of Caatinga plants. Mandevilla tenuiflora (J.C. Mikan) Woodson is indicated for future studies	Strong
8	Nascimento et al., 2013 (27) Ecology of Food and Nutrition	Altinho, PE, Brazil	To compare traditional knowledge regarding food plants in two rural communities in the Caatinga	Ethnobotanical, observational, cross-sectional study	68 people,> 18 years old, living in two Caatinga rural communities	Relationship between knowledge and use of plants with socioeconomic factors, comparing data from two communities	Free list, semi-structured interview and adapted version of 24h Recall	There is a difference in knowledge between communities. Despite extensive knowledge, native species have low frequency of consumption in communities	Strong
9	Santos et al., 2009 (28) Economic Botany	Altinho, PE, Brazil	To analyze the contribution of anthropogenic landscapes to providing useful botanical resources	Ethnobotanical, observational, cross-sectional study	15 people,> 18 years old, living in one Caatinga rural community	Species distribution by categories of use—forage, medicinal, food and timber	Semi-structured interviews and “field herbarium”	The study presents 119 species. Forage was the main category. 10% of the plants have food use, among them Senegalia bahiensis (Benth.) Seigler & Ebinger	Strong
10	Santos et al., 2014 (29) Economic Botany	Crato, CE, Brazil; Caruaru, PE, Brazil	To investigate the usefulness of invasive native and exotic plants for residents of two different communities	Ethnobotanical, observational, cross-sectional study	106 people,> 18 years old, living in two Caatinga rural communities	Relate species considered invasive (native and exotic) with their local perception of usefulness	Semi-structured interviews and plot method for vegetation sampling	55 of the 56 local species considered invasive are considered useful. Participants mentioned 12% of plants as food, among them Passiflora cincinnata Mast	Strong
11	Ferraz et al., 2012 (30) Bosque	Floresta, PE, Brazil	To know the types of use of woody vegetation made by indigenous family farmers	Ethnobotanical, observational, cross-sectional study	30 people,> 18 years old, living in one Caatinga rural community	Categories of use of woody species—food, fodder, fuel, construction	Participant observation and semi-structured interviews	27 species identified. Forage was the main use category. 11% of the plants are mentioned as food, among them Croton blanchetianus Baill	Moderate
12	Juvik et al., 2017 (37) Molecules	Petrolina, PE, Brazil	To identify non-polar constituents of Bromelia laciniosa Mart. ex Schult. & Schult.f., Neoglaziovia variegata (Arruda) Mez and Encholirium spectabile Mart.ex Schult. & Schult.f.	Randomized experimental study	N/A	Fatty acids and their derivatives, very long chain alkanes, vitamins (α and β-tocopherol), triterpenoids and derivatives	Analysis of chemical composition of plants	Plants with high nutritional potential. Highlight for the presence of vitamin E and phytosterols with potential beneficial health effects	Strong
13	Medeiros; Albuquerque, 2014 (33) Journal of Ethnobiology and Ethnomedicine	N/A	To list the food plants described in História Naturalis Braziliae (Piso and Marcgrave, 17th century) with a focus on the Caatinga	Ethnobotanical, historical, descriptive study	N/A	Taxonomic classification, identification of plant parts, forms of consumption and verification of use over time	Historical document analysis and databases search	The use of 80 food species is recommended, such as Spondias tuberosa Arruda and Cereus jamacaru DC. Some lack nutritional studies	Strong
14	Nunes et al., 2018 (31) Journal of Ethnobiology and Ethnomedicine	São Mamede, PB, Brazil; Lagoa, PB, Brazil; Itaporanga, PB, Brazil	To investigate the knowledge of food plants in three communities, comparing communities and gender	Ethnobotanical, observational, cross-sectional study	117 indigenous farmers,> 18 years old, living in three Caatinga rural communities	Comparison of knowledge of native plants in the three communities and their relationship with socioeconomic factors	Semi-structured interviews	26 food species are mentioned, especially Spondias tuberosa Arruda. Knowledge of residents of the three communities is low	Strong
15	Roque; Loiola, 2013 (32) Revista Caatinga	Caicó, RN, Brazil	To identify the main categories of use of native plants in a rural community in the Caatinga	Ethnobotanical, observational, cross-sectional study	23 local experts, > 35 years, living in one Caatinga rural community	Categories of use of native species—medicinal, food, timber, mystical, fuel, forage, domestic use	Semi-structured and structured interviews	The use of 69 species has been described. Medicinal potential related to almost 90% of the plants.11% were food, with emphasis on Ziziphus joazeiro Mart. and S. obtusifolium	Moderate