About

Gail Bornhorst is a Professor and Engineer in the Department of Food Science and Technology and Biological and Agricultural Engineering at the University of California, Davis. Her research focuses on quantitative methods to understand material transport, breakdown, and absorption in the gastrointestinal tract, aiming to improve food safety and quality, enhance consumer health benefits, and optimize food processing operations. She is specifically working on the development of dynamic in vitro models, which, in conjunction with in vivo approaches, are used to deepen the understanding of the relationship between food processing, digestion, and nutrient absorption. Additionally, Dr. Bornhorst investigates methods to utilize food process engineering to optimize functional properties of food, such as nutrient absorption and allergenicity. Her research also explores the mixing and particle dynamics during peristaltic flow to enable a fundamental understanding of the digestion process. Her contributions have been recognized with multiple awards, including being listed among the World's Top 2% Scientists from 2021 to 2024.

Research topics

• Biochemistry
• Chemistry
• Chromatography
• Biotechnology
• Food science
• Biology

Selected publications

• Genotypic and environmental effects on seed coat patterning and nutritional composition in common bean ( <i>Phaseolus vulgaris</i> L.)

  bioRxiv (Cold Spring Harbor Laboratory) · 2026-04-16

  articleOpen access

  Abstract Common bean ( Phaseolus vulgaris L.) is the leading grain legume consumed directly by humans and a primary source of nutrients in many communities. This study utilized common bean genotypes with diverse seed coat phenotypes to investigate genotypic and environmental effects on pigmented seed coat area and seed macronutrient (protein, starch, fat, ash, moisture), anti-nutrient (phytate), and mineral nutrient (iron, zinc, calcium, phosphorus, magnesium, potassium, sodium) profiles. Recombinant inbred lines (RILs) that comprise six phenotypic classes for seed coat patterning and nine commercial cultivars were field-evaluated for multiple years across inland, coastal, and intermountain environments in California. A custom near-infrared spectroscopy calibration improved macronutrient prediction accuracy relative to a pre-existing calibration. Environmental effects on macronutrients were pronounced; the 2022 coastal growing environment was the most distinct, characterized by significantly higher starch and moisture content and significantly lower protein content in the RILs relative to any other environments. Across growing years in the RILs, greater consistency was observed at the inland site, where only protein was significantly different; all macronutrient traits significantly differed within the intermountain site. Certain commercial cultivars largely maintained their relative rank for protein content across environments, indicating consistency of genotypic performance, and Black Nightfall ranked among the highest for iron, zinc, phosphorus, and magnesium. Percent pigmented seed coat area was significantly negatively correlated with both calcium and magnesium concentrations. These results underscore the importance of genotype-by-environment field trials for seed coat patterning, seed nutritional composition, and their interplay, to support breeding of common bean among other grain legumes. Highlights Custom near-infrared spectroscopy (NIRS) calibration improved prediction accuracies Environmental effects significantly influenced common bean macronutrient composition Certain cultivars ranked consistently for macronutrient traits across environments Seed coat pattern was significantly associated with mineral nutrient concentrations

  PublisherDOI

• Upcycling Brazil nut press cake as an ingredient of an innovative spread and evaluation of its nutritional, functional, and sensory properties

  Journal of the Science of Food and Agriculture · 2025-02-24 · 5 citations

  article

  Abstract BACKGROUND Brazil nut press cake (PC), a co‐product of oil extraction, represents a promising alternative for developing sustainable and nutritious food products, meeting the growing demand for healthy and clean‐label options. This study aimed to assess the effects of PC on spread composition, physical characteristics, sensory attributes, consumer acceptance, and storage stability assessed through oil separation. RESULTS Different PC levels (0–100 g kg −1 ) affected spread properties. Higher PC (100 g kg −1 ) levels significantly increased ( P &lt; 0.05) protein content and insoluble fiber (156.3 and 190.0 g kg −1 , respectively). On the other hand, lipids and energy values decreased significantly ( P &lt; 0.05). Instrumental texture analysis revealed that firmness, spreadability, and adhesiveness peaked at the highest PC concentration: 383.87 g, 699.92 g s, and 384.62 g s, respectively. The 100 g kg −1 PC formulation exhibited the lowest oil separation (12%) among samples at 15 000 × g in the sixth week. Sensory analysis showed similar scores for most attributes. The 50 g kg −1 PC formulation scored the highest values for overall acceptance (‘like regularly’), willingness to consume (‘would probably consume’), and to buy (‘maybe buy/maybe not buy’). Correlation analysis indicated that individuals with a controlled lifestyle are more likely to have a balanced diet and pay more for spreads. Principal component analysis suggested that the 50 g kg −1 PC spread is a promising formulation. CONCLUSION These findings underscore the feasibility of using Brazil nut press cake in spreads, advancing the scientific, technological, and socio‐economic uses of a nutritious co‐product. © 2025 Society of Chemical Industry.

  PublisherDOI

• 116. Tracing emptying of fibres differing in physicochemical properties using the Human Gastric Simulator: comparison with in vivo gastric retention times in pigs

  Animal - science proceedings · 2025-08-01

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Ultrasound-treated hybrid protein gels from pea and whey: A comparison of gastric breakdown mechanisms with commercial protein-based foods

  Food Research International · 2025-01-25 · 2 citations

  articleOpen accessSenior author

  : 5.4 µm vs 32.5 µm in control) and resulted in a higher initial Young's modulus than control. Protein hydrolysis at 180 min was ∼53 % lower (p < 0.05) with 15 min ultrasound treatment than control and 7.5 min ultrasound treatment. Hybrid protein gels exhibited similarities in initial Young's modulus to mozzarella (p > 0.05), while ham and paneer were significantly firmer (p < 0.05). Effective diffusivity of moisture from gastric fluid decreased (p < 0.05) in the order: ham > paneer and mozzarella > hybrid protein gels. In contrast, the effective acid diffusivity from gastric fluid was similar (p > 0.05) between hybrid protein gels and paneer, which were ∼74 % higher (p < 0.05) than ham and mozzarella. Digestion time influenced (p < 0.05) breakdown mechanisms (texture, dry matter loss, moisture, and acid uptake) during digestion. This study confirmed that hybrid protein gels were comparable to commercial protein-based foods and the limiting factor driving gastric breakdown is unique to different foods incorporating proteins.

  PublisherDOI

• Comparison of simulated gastrointestinal digestion platforms with varying complexity and sample mass requirements, using common bean ( <scp> <i>Phaseolus vulgaris</i> </scp> L.) as a model

  Journal of the Science of Food and Agriculture · 2025-11-17

  articleOpen accessCorresponding

  BACKGROUND: Measuring bioaccessible nutrient levels during digestion in a physiologically relevant (dynamic) manner is a bottleneck in plant breeding and food product development. The first aim of this study was to develop and compare four simulated gastric digestion models paired with a static small-intestinal phase for use with small sample masses. The four gastric models tested included three dynamic models, which emulate peristaltic contractions with or without additional emulation of enzymatic secretion and flow of food, and one static model. The second aim was to examine bioaccessible nutrient levels in common bean (Phaseolus vulgaris L.) samples representing four genotype by growing environment combinations with differing seed coat coloration, patterning, and phenolic profiles. RESULTS: While the highest bioaccessible nutrient levels (starch and protein hydrolysis, total phenolics, and antioxidant power) were observed from more complex dynamic digestion models, even simple dynamic models showed higher values for these traits than a static digestion model. The use of in vitro models varying in complexity provided insight into nutrient bioaccessibility; for example, differences were observed during digestion between genotypes for protein hydrolysis and between environments for both total phenolics and protein hydrolysis, even in a higher-throughput digestion model. CONCLUSION: Smaller-scale dynamic models show promise as higher-throughput dynamic digestion platforms. These results inform the application of simulated digestion models to assay bioaccessible nutrient levels in plant-based foods. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  PublisherOA PDFDOI

• Fracture and rheological properties of standardized, model solid foods influence their breakdown mechanisms during in vitro gastric digestion with simulated peristalsis

  Food Hydrocolloids · 2025-05-27 · 2 citations

  articleSenior authorCorresponding
  PublisherDOI

• Brazil nut press cake-enriched spread: unveiling in vitro gastrointestinal digestion behavior and its effects on nutrient release

  Food Research International · 2025-08-08 · 1 citations

  articleOpen accessSenior authorCorresponding

  Limited research has been done to understand the digestion of Brazil nut press cake, a byproduct of Brazil nut oil processing that is increasingly used as a food ingredient. This study aimed to investigate the impact on digestion parameters and nutrient release of varying concentrations of press cake in a spread consumed as part of a meal during dynamic in vitro gastrointestinal digestion. Simulated meals containing toasted bread with different spreads formulations (varying 0, 5, or 10 % of spread mass as press cake), and one meal without spread as control, were submitted to in vitro oral digestion, in vitro gastric digestion in the Human Gastric Simulator (HGS), and a static in vitro small intestinal digestion. Meals with Brazil nut spread exhibited a pH range of 5.30 to 5.36 after 30 min, gradually decreasing to ∼1.4 by 180 min. Meal and digestion time significantly influenced the gastric emptying of dry matter and lipids ( p < 0.05), with no significant differences ( p > 0.05) between emptying for any meals containing spread, possibly due to the formation of emulsified structures. During digestion, starch hydrolysis showed maximum release after 60 and 90 min for meals of spread and bread, respectively. The 0 and 5 % spread-based meals achieved a total protein release of 76 %, while the 10 % PC reached just 58 %. This study provides insights into Brazil nut press cake utilization within meals, revealing the nutrient release differed significantly with the spread meals, delaying starch, protein, fatty acid, and polyphenol release, particularly during small intestinal digestion. • Brazil nut spreads affect digestion kinetics during in vitro gastric digestion. • Press cake addition does not alter breakdown of spread meal. • Protein release was reduced in meals with 10 % press cake compared to lower ratios. • Press cake enhanced fatty acid and polyphenol release during intestinal phase. • Press cake in spreads may delay nutrient release when evaluated in a meal.

  PublisherDOI

• A proposed framework to establish<i>in vitro</i>–<i>in vivo</i>relationships using gastric digestion models for food research

  Food & Function · 2024-01-01 · 4 citations

  reviewOpen accessSenior authorCorresponding

  Proposal of an in vitro – in vivo relationship (IVIVR) framework for food digestion research that serves as a tool to evaluate and improve a specific in vitro approach in simulating in vivo gastric digestion process.

  PublisherOA PDFDOI

• Optimization of sulforaphane bioavailability from a glucoraphanin-rich broccoli seed extract in a model of dynamic gastric digestion and absorption by Caco-2 cell monolayers

  Food & Function · 2024-12-05 · 8 citations

  articleCorresponding

  small intestinal digestion, and (ii) increase SF bioavailability in Caco-2 cell monolayers, a model of human intestinal epithelium. Addition of exogenous Myr increased the conversion of GR to SF in free powder during small intestinal digestion, but not during gastric digestion, where Myr activity was inhibited by the acidic environment. Capsule delivery of BSE[GR]/MSP[Myr] (w/w ratio 4 : 1) resulted in a 2.5-fold higher conversion efficiency compared to free powder delivery (72.1% compared to 29.3%, respectively). AA combined with MSP[Myr] further enhanced the conversion efficiency in small intestinal digestion and the bioavailability of SF in Caco-2 cell monolayers. Bioavailability of GR as SF, SF metabolites, and GR was 74.8% in Caco-2 cell monolayers following 30 min gastric digestion and 60 min small intestinal digestion. This study highlights strategies to optimize GR bioconversion in the upper GI tract leading to enhanced SF bioavailability.

  PublisherDOI

• Surveying Student Interest in the Biological Systems Engineering Major

  2024-02-06

  articleOpen accessSenior author

  An anonymous student survey developed

  PublisherOA PDFDOI

Frequent coauthors

• R. Paul Singh

  University of California, Davis

  112 shared

• Joanna Nadia

  Massey University

  69 shared

• Harjinder Singh

  Massey University

  66 shared

• Parthasarathi Subramanian

  Massey University

  48 shared

• Natascha Stroebinger

  Massey University

  42 shared

• Suzanne M. Hodgkinson

  Massey University

  42 shared

• Yamile A. Mennah‐Govela

  University of California, Davis

  35 shared

• Alexander G. Olenskyj

  University of California, Davis

  31 shared

Awards & honors

• World's Top 2% Scientists (2021)
• World's Top 2% Scientists (2022)
• World's Top 2% Scientists (2023)
• World's Top 2% Scientists (2024)