César Augusto Napa Almeyda

Dr. César Augusto Napa Almeyda

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

View All Publications
14 August 2023 in Fermentation
Verified
Journal Article
Open access
PDF file
CACésar Augusto Napa Almeyda
César Augusto Napa Almeyda
CCCelia Criado
Celia Criado
JMJhony Mayta-Hancco
Jhony Mayta-Hancco
Marcial Ibo SILVA - JAIMESMarcial Ibo SILVA - JAIMES
Marcial Ibo SILVA - JAIMES
LHLuis Alberto Condezo Hoyos
Luis Alberto Condezo Hoyos
Maria A. Del Pozo BayónMaria A. Del Pozo Bayón
Maria A. Del Pozo Bayón
In this study, we aimed to isolate and phenotypically characterize non-Saccharomyces yeast strains (NSYSs) from the skin of aromatic (Italy) and non-aromatic (Negra Criolla) grapes from vineyards in Moquegua, Peru, typically used for the production of pisco. Our second objective was to characterize the volatile compounds and sensory attributes of pisco made from these grapes. Pichia terricola (56%), Metschnikowia pulcherrima (31%), and Naganishia vaughanmartiniae (13%) were the main NSYSs isolated from the skin of aromatic Italy grapes and identified; meanwhile, Vishniacozyma carnescens (50%), Vishniacozyma heimaeyensis (30%), and Aureobasidium pullulans (20%) were identified on the skin of the non-aromatic Negra Criolla grapes. These NSYSs showed different capacities in terms of carbohydrate fermentation, polygalacturonase activity, ethanol tolerance, sulphite production, and nitrogen consumption. Moreover, the pisco resulting from these varieties of grape had different volatile profiles. Terpene alcohols such as citronellol, geraniol, linalool, and nerol were found in pisco made from Italy grapes, while higher contents of 2-phenylacetate and ethyl esters were found in Negra Criolla Pisco. Intermediate levels of both 1-hexanol and bencyl alcohol were also found in all the pisco. Sensory analysis performed by a trained pisco tasting panel showed that citric, floral, alcohol, and syrup descriptors were more marked in Italy Pisco, while nuts, syrup, alcohol, and floral were the most intense attributes of Negra Criolla Pisco. These results will contribute to determining the potential of indigenous grape yeasts from the Moquegua region as fermentation starters to improve the typical sensory qualities of the pisco produced in this region, which deserves further study.

27 May 2025 in Beverages
Verified
Journal Article
Open access
PDF file
ESErick Saldaña
Erick Saldaña
JMJennifer Daniela Alvarez Mamani
Jennifer Daniela Alvarez Mamani
JLJaime Laqui-Estaña
Jaime Laqui-Estaña
KEKarina Eduardo
Karina Eduardo
JMJuan Dario Rios Mera
Juan Dario Rios Mera
JMJhony Mayta-Hancco
Jhony Mayta-Hancco
Pisco is an emblematic spirit in Peru and Chile, made from fermented grapes, gaining growing scientific interest over the last two decades. This study aimed to map 20 years of research on Pisco through a systematic bibliometric review. A search was conducted in the Scopus database covering the period from 2004 to 2024, applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology for the transparent selection of scientific articles. The search strategy considered titles, abstracts, and keywords, using the terms “Pisco” and “schnapps”, excluding unrelated fields such as geology (basin, seismic, fossil). The initial search yielded 360 records. After removing non-original articles (books, book chapters, conference papers, and reviews), 101 articles remained. A further screening excluded irrelevant studies (e.g., those referring to the city of Pisco rather than the beverage), resulting in 78 articles included for final analysis. It was observed that 19% of the studies focus on the history, culture, and appellation of origin; 14% on environmental sustainability; 10% on innovation and quality; and 9% on the bioactive properties of by-products. Other areas include extraction technologies (9%), distillation process modeling (8%), and marketing and economics (8%), among others. Recent trends are related to clean production practices. Thus, Pisco by-products and their components can be exploited by applying technologies such as supercritical fluids, drying, and biofilms, while, for waste management, the processes of composting, solar photo-Fenton, and ozonation can be applied. Moreover, it is important to highlight that the valorization of Pisco by-products opens opportunities for translation into the market, particularly in developing cosmetics, nutritional supplements, and bio-packaging materials, contributing to sustainability and innovation in new industries. However, a more holistic view is still needed in Pisco research. These findings suggest that future research should prioritize the integration of consumer-based sensory evaluations and sustainable production innovations to optimize Pisco’s quality, enhance market acceptance, and promote environmentally responsible industry practices.

23 December 2024 in Beverages
Verified
Journal Article
Open access
PDF file
CACésar Augusto Napa Almeyda
César Augusto Napa Almeyda
Carolina MunozCarolina Munoz
Carolina Munoz
Marcial Ibo SILVA - JAIMESMarcial Ibo SILVA - JAIMES
Marcial Ibo SILVA - JAIMES
LHLuis Alberto Condezo Hoyos
Luis Alberto Condezo Hoyos
Maria A. Del Pozo BayónMaria A. Del Pozo Bayón
Maria A. Del Pozo Bayón
The objective of this study was to investigate the impact of co-fermentation of Italia and Negra Criolla grape musts using non-Saccharomyces yeast strains (NSYSs) isolated from both grape varieties, on the major volatile compounds and sensory characteristics of Piscos (distilled spirits). Native NSYSs previously isolated from Italia (Pichia terricola, Metschnikowia pulcherrima, and Naganishia vaughanmartiniae) and Negra Criolla (Vishniacozyma carnescens, Vishniacozyma heimaeyensis, and Aureobasidium pullulans) grapes’ skins were inoculated at the beginning of grape must fermentation. A centroid simplex design was applied in order to obtain 10 representative yeast blends for use as mono- (n = 3), bi- (n = 3), and ternary (n = 4) inoculations. Additionally, a control sample without inoculum was also set up. For each yeast blend, the volatile composition and sensory characteristics of Piscos were evaluated. Results showed that mono-inoculation using specific NSYSs, such as P. terricola, M. pulcherrima, and N. vaughanmartiniae, led to a notable predominance of some terpenes such as α-terpineol, citronerol, and geraniol in Pisco from Italia grapes compared to the control Pisco. Conversely, in Pisco from Negra Criolla grapes, where V. carnescens, V. heimaeyensis, and A. pullulans were used in a similar mono-inoculation process, a higher presence of phenylethyl alcohol and 2-phenylethyl acetate compared to the control was observed. The sensory analysis revealed that citrus, floral, alcohol, and syrup descriptors had a higher intensity in mono-inoculated Pisco Italia, whereas spice, herbaceous, and cooked vegetable descriptors had the highest intensity in Negra Criolla Piscos produced with ternary NSYS inoculum inoculations. This study demonstrates that the use of native non-Saccharomyces yeast strains in the co-fermentation of grape musts can significantly influence the volatile profile and sensory characteristics of Pisco. These findings will allow us to establish new inoculation strategies to impact the overall sensory and aromatic profile of the Piscos produced with different grape varieties.