Processing hemp seeds into foods generates several by-products that are rich in nutrients and bioactive phytochemicals. This paper presents a thorough plant metabolite analysis and a comprehensive assessment of the nutrient content of 14 hemp seed-based foods and by-products and evaluates their feasibility to deliver dietary needs and daily recommendations. The protein-85-product was the hemp food and hemp fudge the hemp by-product with the highest content of protein, 93.01 ± 0.18% and 37.66 ± 0.37%, respectively. Hemp seed-hull flour had the richest insoluble non-starch polysaccharide content (39.80 ± 0.07%). Linoleic acid was the most abundant fatty acid across all the hemp seed-based samples (ranging from 53.80 ± 2.02% in the protein-85-product to 69.53 ± 0.45% in the hemp cream). The omega-6 to omega-3 fatty acid ratio varied from 3:1 to 4:1 across all hemp seed-based samples. The majority of hemp seed-based samples were rich sources of potassium, magnesium, and phosphorus. Gentisic acid, p-coumaric acid, and syringaresinol were the most abundant plant metabolites measured and found mainly in bound form. Hemp seed by-products are valuable sources of nutrients capable of meeting dietary needs and, therefore, should be re-valorized into developing healthy food formulations to deliver a truly zero-waste hemp food production.

Pseudo-cereals such as buckwheat (Fagopyrum esculentum) are valid candidates to promote diet biodiversity and nutrition security in an era of global climate change. Buckwheat hulls (BHs) are currently an unexplored source of dietary fibre and bioactive phytochemicals. This study assessed the effects of several bioprocessing treatments (using enzymes, yeast, and combinations of both) on BHs’ nutrient and phytochemical content, their digestion and metabolism in vitro (using a gastrointestinal digestion model and mixed microbiota from human faeces). The metabolites were measured using targeted LC-MS/MS and GC analysis and 16S rRNA gene sequencing was used to detect the impact on microbiota composition. BHs are rich in insoluble fibre (31.09 ± 0.22% as non-starch polysaccharides), protocatechuic acid (390.71 ± 31.72 mg/kg), and syringaresinol (125.60 ± 6.76 mg/kg). The bioprocessing treatments significantly increased the extractability of gallic acid, vanillic acid, p-hydroxybenzoic acid, syringic acid, vanillin, syringaldehyde, p-coumaric acid, ferulic acid, caffeic acid, and syringaresinol in the alkaline-labile bound form, suggesting the bioaccessibility of these phytochemicals to the colon. Furthermore, one of the treatments, EC_2 treatment, increased significantly the in vitro upper gastrointestinal release of bioactive phytochemicals, especially for protocatechuic acid (p < 0.01). The BH fibre was fermentable, promoting the formation mainly of propionate and, to a lesser extent, butyrate formation. The EM_1 and EC_2 treatments effectively increased the content of insoluble fibre but had no effect on dietary fibre fermentation (p > 0.05). These findings promote the use of buckwheat hulls as a source of dietary fibre and phytochemicals to help meet dietary recommendations and needs.

Agricultural hemp (Cannabis sativa L.) is currently underutilised for food and could be pivotal to the development and expansion of a low-carbon food production system and to contribute to sustainable diets. Dehulling hempseed for food (for hempseed hearts) generates several by-products, including hempseed “screenings”. This study assessed the effects of several bioprocessing treatments (using enzyme mixtures, yeast, and combinations of both) on hemp screenings nutrient and phytochemical content and their digestion and metabolism in vitro (using a gastrointestinal digestion model and incubations with human mixed microbiota-faecal samples from three healthy donors). The nutrients and phytochemicals’ metabolites were measured using targeted LC-MS/MS and GC analysis. The hempseed screenings are rich in insoluble NSP (16.46 ± 0.86%), protein (20.15 ± 0.11%, with 3.83% tryptophan), syringaresinol, p-coumaric and protocatechuic acids. The hempseed screenings are highly fermentable, resulting in a significant increase in acetic, propionic, and butyric acids following fermentation with faecal microbiota. The bioprocessing treatments significantly increased the extractability of the phytochemicals, especially in free and alkaline-labile forms, without improving the fibre fermentation. The findings from this study support the use of hempseed screenings as a source of dietary nutrients for biodiversification and development of potential functional foods for metabolic and gut health.

Limited data exists on the combined nutritional and phytochemical profiles of UK commercially available plant-based foods, limiting comprehensive compositional data available for dietary assessment and food formulation. This study addresses this gap by providing thorough compositional analysis of quinoa (red, black, organic), chia seeds (organic, white), pumpkin seeds (conventional, organic), flaxseeds (brown, golden, organic), and triticale grain (organic, cereal meal, rolled), profiling macronutrients, dietary fiber, amino acids, fatty acids, essential minerals, and bioactive phytochemicals. Pumpkin seeds exhibited the highest protein (29–36%) and fat (42–46%) contents, markedly exceeding quinoa and triticale, highlighting their role as a plant-based protein and energy source. Flaxseeds and chia seeds provided the greatest dietary fiber (15 g/100 g), while mineral analysis identified pumpkin seeds as particularly rich in phosphorus and magnesium, and white chia seeds as a rich source of calcium and iron. Targeted LC-MS/MS and HPLC screening (171 molecules) revealed substantial variation in phytochemical composition among products with red quinoa, golden flaxseed, and white chia seed containing the highest concentrations of quantified phytochemicals (up to 97.2 mg/100 g). These findings provide integrated data on the nutrient and phytochemical composition of selected commercially available products, reinforcing the practical importance of crop diversity for enhancing dietary nutrient and phytochemical diversity and informing future research, food innovation, and dietary assessment initiatives involving plant-based foods.