Expanding Paleoindian Diet Breadth: Paleoethnobotany of Connley Cave 5, Oregon, USA

Paleoethnobotanical perspectives are essential for understanding past lifeways yet continue to be underrepresented in Paleoindian research. We present new archaeobotanical and radiocarbon data from combustion features within stratified cultural components at Connley Caves, Oregon, that reaffirm the inclusion of plants in the diet of Paleoindian groups. Botanical remains from three features in Connley Cave 5 show that people foraged for diverse dryland taxa and a narrow range of wetland plants during the summer and fall months. These data add new taxa to the known Pleistocene food economy and support the idea that groups equipped with Western Stemmed Tradition toolkits had broad, flexible diets. When viewed continentally, this work contributes to a growing body of research indicating that regionally adapted subsistence strategies were in place by at least the Younger Dryas and that some foragers in the Far West may have incorporated a wider range of plants including small seeds, leafy greens, fruits, cacti, and geophytes into their diet earlier than did Paleoindian groups elsewhere in North America. The increasing appearance of diverse and seemingly low-ranked resources in the emerging Paleoindian plant-food economy suggests the need to explore a variety of nutritional variables to explain certain aspects of early foraging behavior.

Comparative Study of Sensory Attributes of Leafy Green Vegetables Grown Under Organic and Conventional Management

This study was carried out to compare the sensory qualities of leafy green vegetables (collard, kale, lettuce and swiss chard) grown under organic and conventional production systems. Four leafy greens were produced on an organically and conventionally managed research farm of Tennessee State University, Nashville, TN in Spring 2019 and 2020. Crops in a conventional field were grown in the open field, whereas in organic field crops were grown in the open and under three different row covers (agribon cloth, insect net and plastic). Row covers in organic systems were used to protect crops from insect damage. Plant samples were collected from all the treatments and evaluated for sensory qualities including color, texture, taste, odor and flavor following two approaches i.e., instrumental and via consumer panel perception. Consumer panel perception results showed minor differences in the sensory qualities between organic and inorganically produced leafy greens. Instrumental methods showed no differences in color parameters of kale, lettuce and swiss chard grown under organic and conventional production systems. In collard, the lightness (L*), b* (yellow-blue axis), brightness (Y) and chroma (C) values were higher in conventional, while hue angle was higher in organic (open). There were no differences in instrumental textural values of organically and conventionally grown leafy greens. Among row covers, the textural value of collard and kale was higher in open relative to row covers. The content of main quality contributors 1-Hexanol was higher in conventionally grown collard compared to organic (open). Aldehyde compound was higher in organically grown kale and trans-hex-2-enyl-acetate (Ester) compound was higher in conventionally grown kale. Monoterpenes were higher in organic lettuce and ketones were higher in conventionally grown lettuce. Overall, there were not many differences in the sensory qualities of leafy greens grown under organic and conventional production systems. Further comparative studies between organic and conventional systems on sensory qualities of leafy greens are needed.

Pathogenic Escherichia coli: An Overview on Pre-Harvest Factors that Impact the Microbial Safety of Leafy Greens

Consumption of fresh leafy greens has been repeatedly reported and linked to pathogenic Escherichia coli-associated foodborne illnesses outbreaks. Leafy greens are mostly eaten raw, based on the increased consumers’ preferences for natural, nutritious diets. Recent studies indicate the incidence of infections caused by pathogenic Escherichia coli remained almost unchanged or even increased. In this context, fresh produces increased the awareness about their primary contamination level, namely the pre-harvest phase. Fully eliminating pathogenic Escherichia coli from pre-harvest environment proved to be impossible. Emphasis must be placed on the pre-harvest factors that affect the food safety and, subsequently, on the identification of possible mitigation strategies that can be used on-farm for reducing the risk of leafy greens contamination with pathogenic Escherichia coli.

Spatial Characterization of Microbial Communities on Multi-Species Leafy Greens Grown Simultaneously in the Vegetable Production Systems on the International Space Station

The establishment of steady-state continuous crop production during long-term deep space missions is critical for providing consistent nutritional and psychological benefits for the crew, potentially improving their health and performance. Three technology demonstrations were completed achieving simultaneous multi-species plant growth and the concurrent use of two Veggie units on the International Space Station (ISS). Microbiological characterization using molecular and culture-based methods was performed on leaves and roots from two harvests of three leafy greens, red romaine lettuce (Lactuca sativa cv. ‘Outredgeous’); mizuna mustard, (Brassica rapa var japonica); and green leaf lettuce, (Lactuca sativa cv. Waldmann’s) and associated rooting pillow components and Veggie chamber surfaces. Culture based enumeration and pathogen screening indicated the leafy greens were safe for consumption. Surface samples of the Veggie facility and plant pillows revealed low counts of bacteria and fungi and are commonly isolated on ISS. Community analysis was completed with 16S rRNA amplicon sequencing. Comparisons between pillow components, and plant tissue types from VEG-03D, E, and F revealed higher diversity in roots and rooting substrate than the leaves and wick. This work provides valuable information for food production-related research on the ISS and the impact of the plant microbiome on this unique closed environment.