Three novel endo-β-N-acetylglucosaminidases (AVUL01, BCAC01, and BFIN01) classified as members of the glucoside hydrolase (GH) family 18 were identified from human fecal samples and then cloned and characterized for their ability to hydrolyze two distinct classes of N-glycans. Endo-β-N-acetylglucosaminidases (ENGases) are known for the hydrolysis of chitin and the N,N′-diacetylchitobiose core of N-linked glycans, depending on the glycan architecture. N-glycans have shown bioactivity as substrates in the human gut microbiome for microbes that encode ENGases, thus demonstrating their ecological relevance in the gut. However, distinct types of N-glycan structures, for example, oligomannosidic or complex, have been shown to enrich different microbes within the human gut. Novel advances in food technology have commercialized animal-derived dietary proteins with oligomannosidic instead of traditionally complex N-glycans using precision fermentation. This indicates that there is an unmet need to identify the classes of N-glycans that gut-derived ENGases act upon to determine whether these novel proteins alter gut ecology. AVUL01, BCAC01, and BFIN01 all demonstrated activity on exclusively oligomannosidic N-glycans from RNase B and bovine lactoferrin; however, they failed to show activity on complex or α-1,3-core fucosylated high-mannose N-glycans derived from fetuin and horseradish peroxidase, respectively. These results suggest that α-1,3 core fucosylation and complex N-glycan architecture inhibit the activity of AVUL01, BCAC01, and BFIN01. Furthermore, BFIN01 performed significantly better than BCAC01, resulting in a greater amount of N-glycans, suggesting that certain ENGases may possess enhanced specificity and kinetics as an evolutionary strategy to compete for resources.

To address consumer demand for “clean label” meat products, naturally derived nitrite sources are increasingly used as alternatives to synthetic nitrite. This study assessed the effects of curing source and high-pressure processing (HPP; 85,000 psi) on the quality of smoked, sliced ham. Hams were produced by following four formulations: synthetic nitrite (CONV), celery powder plus antimicrobial (ALT), celery powder with spices (ALTSPI), and no nitrite plus spices (UNCSPI), each with or without HPP. Instrumental color, texture, moisture, and sensory attributes were evaluated over 29 days of refrigerated vacuum display. CONV and ALT hams exhibited comparable color stability, texture, and overall sensory acceptability, indicating that natural nitrite effectively preserves cured meat characteristics. UNCSPI hams showed lower redness, altered hue, reduced springiness, and inferior sensory scores, confirming nitrite’s functional necessity. HPP minimally affected color, texture, or acceptability in nitrite-containing hams but increased off-flavor in uncured formulations, likely due to lipid oxidation. These results demonstrate that naturally sourced nitrite performs equivalently to synthetic nitrite in maintaining quality and support regulatory recognition of naturally cured products. Additionally, HPP does not compromise quality in nitrite-containing RTE hams.