Hans Fröder

Dr. Hans Fröder


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
3 January 2023 in Fermentation
Verified
Journal Article
Open access
PDF file
MEMagnólia Martins M Erhardt
Magnólia Martins M Erhardt
Wemerson Castro de OliveiraWemerson Castro de Oliveira
Wemerson Castro de Oliveira
HFHans Fröder
Hans Fröder
PMPedro Henrique Marques
Pedro Henrique Marques
Beatriz OliveiraBeatriz Oliveira
Beatriz Oliveira
NRNeila Silvia Pereira dos Santos Richards
Neila Silvia Pereira dos Santos Richards
Artisanal cheese, produced with raw milk by a predominantly manual approach, has a historical and cultural tradition related to the region of origin. Given its economic and cultural importance, the main objective of this study was to investigate and characterize the diversity of lactic acid bacteria (LAB) of artisanal cheeses produced and traded by family agro-industries in a region of southern Brazil. The LAB composition of artisanal cheese samples, belonging to different municipalities of the Region of Vale do Taquari, were characterized by the next-generation sequencing (NGS) method, amplifying the V3/V4 region of the 16S rRNA gene. A total of 35 LAB species, distributed in seven genera, were identified, and rarefaction analysis suggested that the total diversity assessed by 16S rRNA analysis was high in the analyzed samples. The average Ph ranged from 4.6 to 6.6, and a correlation with the genus Lactococcus (r = 0.62) was the most expressive. The LAB genera identified in the cheese samples were Bavariicococcus, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Marinillactibacillus, and Pediococcus. Lactococcus lactis was the most predominant species, present in all samples. Although some species have been identified in the three altitudes studied, the abundance varied according to geographic environments. Enterococcus italicus is more present at high altitudes, unlike Lactococcus plantarum and Lactococcus raffinolactis at low altitudes. Lactococcus lactis was present in the three geographic environments evaluated, but the highest abundance was observed at high altitudes. The identification of LAB present in fermented cheeses is essential to understand the organoleptic quality during the maturation process as well as to establish the shelf life, including the safety and the overall quality of the cheese. This specific microbiota contributes to the flavor and unique characteristics of the regional dairy products, and on the other hand can be a source of specific starter cultures that guarantee the product’s identity.

12 August 2025 in Food Microbiology
Verified
Journal Article
Closed access
HFHans Fröder
Hans Fröder
ALAndré Bittencourt Lorusso
André Bittencourt Lorusso
GMGustavo Sganzerla Martinez
Gustavo Sganzerla Martinez
RMRenata Ernlund Freitas de Macedo
Renata Ernlund Freitas de Macedo

18 July 2021 in Research, Society and Development
Verified
Journal Article
Open access
PDF file
HFHans Fröder
Hans Fröder
MMMárcio Lutero Mafalda Martins
Márcio Lutero Mafalda Martins
Wemerson Castro de OliveiraWemerson Castro de Oliveira
Wemerson Castro de Oliveira
JMJaqueline Lidorio de Mattia
Jaqueline Lidorio de Mattia
Em uma era globalizada, a falta de tempo, a comodidade, as preferências individuais e o próprio estilo de vida das pessoas, fazem com que, a cada ano, o número de refeições consumidas fora de casa cresça. Embora esse movimento seja uma alternativa econômica, essa praticidade fez com que houvesse um aumento no número de surtos alimentares. Essa revisão de literatura tem por objetivo abordar sobre os principais patógenos e problemas encontrados em alimentos comercializados na rua. Os dados das referências apontam que as contaminações de alimentos de rua são frequentes e um risco à saúde pública. É necessário um plano de intervenções e capacitações dos vendedores ambulantes, quanto a higienização correta de todos os processos de produção, para garantir a segurança alimentar dos consumidores. Além disso, uma estrutura básica adequada para o vendedor é essencial para priorizar a qualidade na oferta dos alimentos.

1 January 2025 in Brazilian Archives of Biology and Technology
Verified
Journal Article
Open access
PDF file
MRMarion Ruis
Marion Ruis
HFHans Fröder
Hans Fröder
KPKarla Joseane Perez
Karla Joseane Perez
Heat treatment used in milk powder processing cannot always inactivate spore-forming microorganisms. Toxin deterioration and production by some species are significant concerns for the dairy industry, making the identification of these microorganisms essential for solving problems with the quality of the products. Given this scenario, this study sought to quantify and identify the predominant species in milk powder, aiming to know the isolated genetic varieties. Fourteen samples were analyzed for aerobic/anaerobic, mesophilic, and thermophilic bacterial spore presence, totaling 52 analyses. Spore contamination was verified in all samples analyzed, and the thermophilic spores had the highest contamination levels. 16S rRNA sequencing revealed 47 isolates: Weizmannia coagulans (21%), Anoxybacillus flavithermus (5.3%), Clostridium butyricum (5.3%), Bacillus amyloliquefaciens (2.6%), Geobacillus stearothermophilus (2.6%), Clostridium pabulibutyricum (2.6%), Clostridium sporosphaeroides (2.6%), Bacillus licheniformis (2.6%), Bacillus sp. (34%), Geobacillus sp. (15.8%), and Clostridium sp. (5.3%). The results indicate the need to establish control measures to improve the hygiene and processing conditions of powdered milk, thereby ensuring product quality and consumer safety.

26 September 2022 in Research, Society and Development
Verified
Journal Article
Open access
PDF file
MEMagnólia Martins M Erhardt
Magnólia Martins M Erhardt
HFHans Fröder
Hans Fröder
Wemerson Castro de OliveiraWemerson Castro de Oliveira
Wemerson Castro de Oliveira
Jeferson Aloísio StröherJeferson Aloísio Ströher
Jeferson Aloísio Ströher
PSPaulo Roberto Savergnini
Paulo Roberto Savergnini
NRNeila Silvia Pereira dos Santos Richards
Neila Silvia Pereira dos Santos Richards
A produção de queijo artesanal, especialmente as que conservam aspectos produtivos culturalmente repassados entre gerações, está cada vez mais valorizada pelos consumidores, entretanto, as normativas vigentes exigem as boas práticas agropecuárias e de fabricação de alimentos como requisitos imprescindíveis. Com o objetivo de conhecer a tradição da produção deste queijo na região do Vale do Taquari-RS, foram realizadas visitas a 5 propriedades rurais (codificadas do nº 1 ao 5). Na ocasião, foram acompanhadas a ordenha dos animais, analisando-se as Boas Práticas Agropecuárias (BPA) e as Boas Práticas de Fabricação (BPF) dos queijos. Foram coletadas amostras dos leites utilizados cujas análises físico-químicas apresentaram inconformidade para: acidez titulável 20%, índice crioscópico 40%, antibióticos betalactâmicos 40%, presença de cloretos 20%, lactose anidra 20% e sólidos não gordurosos 20%; e contagem de células somáticas (CCS) 40%; os demais padrões apresentaram conformidade. As amostras dos queijos foram coletadas com 7, 15 e 60 dias de maturação e analisadas quanto às suas características físico-químicas e microbiológicas. A média de umidade dos queijos foi de 46 a 54,9% e embora a refrigeração do leite, estocagem estejam ocorrendo dentro do tempo/temperatura previstos, algumas operações realizadas carecem de maiores cuidados visto que no aspecto microbiológico, 100% das amostras estavam impróprias para consumo por contaminação por Staphylococcus aureus; 60% fora dos padrões para coliformes totais. Sendo que uma amostra apresentou níveis acima dos padrões estabelecidos na legislação para Staphylococcus aureus, coliformes totais e Escherichia coli. Concluiu-se que as boas práticas agropecuárias e de fabricação adotadas nas propriedades rurais, mostraram-se insuficientes o que refletiu nos resultados obtidos, muitas adequações se fazem necessárias para que os queijos artesanais estejam em conformidade com a legislação brasileira para uso de leite cru no processamento de queijos, bem como produção de queijos artesanais.

14 January 2026 in Biologia
Verified
Journal Article
Open access
PDF file
BGBrenda Picoli Gheno
Brenda Picoli Gheno
HFHans Fröder
Hans Fröder
TLTamiris Silva Lopes
Tamiris Silva Lopes
VRVitor Braga Rissi
Vitor Braga Rissi
SSScheila de Avila e Silva
Scheila de Avila e Silva
Primer design constitutes a critical step in the Polymerase Chain Reaction (PCR), directly influencing the efficiency, specificity, and reliability of amplification. This review evaluates widely used open-access primer design tools — including Primer3Plus, Primer-BLAST, QuantPrime, OligoArchitect™, GenScript, Eurofins PCR Primer Design Tool, BiSearch, STITCHER 2.0, and PrimerQuest™ — with an emphasis on design parameters, usability, and limitations. The use of these platforms enables integration with databases of pathogen genes, biomarkers, and other targets, thereby expanding the applicability of analyses in complex molecular studies. Despite these advances, many tools still lack integrated specificity validation, necessitating experimental confirmation to ensure accurate results. To guide researchers in selecting the most appropriate platform, this review presents a comparative table highlighting the main strengths and limitations of each software. By providing an overview of the capabilities and constraints of these tools, the study supports informed decision-making and the optimized development of PCR assays across diverse research contexts. The analysis emphasizes the balance between automation and empirical validation, underscoring that tool selection is pivotal for obtaining reliable and efficient molecular data.