March 12, 2024 - Renee Lee (Wiedmann Lab) & Hector Ramirez (Goddard Lab)

Renee Lee

MS Candidate, Wiedmann Lab

Department of Food Science, Cornell University

Baseline spore levels and characterization of aerobic and anaerobic sporeformers in US organic raw milk

Abstract

The pressures to expand the organic dairy industry require the improvement of organic dairy product quality. Sporeforming bacteria primarily enter the dairy product continuum at the farm level, as they are found ubiquitously in the dairy farm environment (e.g. soil, water, feed, etc.), are able to survive processing hurdles, and subsequently grow in finished products. Sporeforming bacteria from the orders Bacillales and Clostridiales are frequently associated with dairy spoilage and food safety concerns. To improve overall raw milk quality, it is essential to first benchmark the presence of sporeforming bacteria contamination in the US organic dairy continuum at the farm level. To do so, a multi-regional study was conducted where raw milk samples were collected every 2 months for 12 months from 102 organic dairy farms across 11 states. Sporeforming bacteria levels were assessed using 4 spore tests: Mesophilic Spore Count (MSC), Thermophilic Spore Count (TSC), Psychrotolerant Spore Count - Most Probable Number (PSC MPN), and Butyric-Acid Bacteria - Most Probable Number (BAB MPN). A total of 3,088 aerobic sporeformers and 1,083 anaerobic gas-producing sporeformers were isolated and characterized using rpoB and 16S rDNA sequencing, respectively. The results thus far revealed a substantial microbial diversity of aerobic and anaerobic sporeforming bacteria in organic raw milk. The aerobic sporeforming bacteria isolated were predominantly Bacillus and Paenibacillus and the anaerobic sporeforming bacteria isolated were largely represented by Clostridium and Bacillus. The baseline spore level and characterization serves as the first step to a systems approach to improve quality and shelf-life of organic dairy products.

Héctor Ramírez

Ph.D. Candidate, Goddard Lab

Department of Food Science, Cornell University

Improving performance and sustainability of food packaging: active packaging technologies to expand the use of aluminum cans

Abstract

Replacement of Bisphenol A (BPA) based coatings in food contact materials has been of industrial interest for decades due to health concerns and consumer perception. Although potential replacements have been released to the market, match the high resistance to corrosion of BPA-based resins across food matrices has been the biggest challenge. Failing to protect the metal container from the onset of corrosion during the shelf-life of foods and beverages, puts at risk its quality and safety for the consumer.

Biomass-derived unsaturated polyesters (UP) are versatile and sustainable low molecular-weight thermoplastics that can be functionalized and crosslinked for potential use as resin or additives in coating formulations.

This work focuses on the synthesis, post-functionalization, and thermal crosslinking of unsaturated copolyesters. The aim is to increase the corrosion resistance of current polyester-based coatings through the post-functionalization of UPs with corrosion-protective monomers including phenolic or triazole moieties. Thermal, mechanical, surface, and electrochemical characterizations are performed to assess the potential use as coatings for diverse food matrices involving the different packaging technologies.