Effects of oregano essential oil on the ruminal pH and microbial population of sheep

The feeding of Co lactate (Co), an essential oil blend (EO; oregano), or a combination of Co and EO (EOC) may improve nutrient digestion of corn silage-based rations. In four separate studies, Co, EO, or EOC was fed at 0, 4, and 7 g/days to nine rumen fistulated rams arranged in a replicated 3 × 3 Latin square design. The fourth study evaluated the carrier at 0, 4, and 7 g/day. In each ram, fresh ensiled corn silage, leaf, and husk were placed in individual nylon bags inserted through the ruminal cannula and removed after 48 h. Rams fed increasing carrier rates demonstrated similar (P > 0.10) nutrient digestibilities and ruminal pH and volatile fatty acid concentrations. Feeding Co at 4 and 7 g/day increased (P < 0.05) digestibility of DM (59.4, 63.9, and 62.4% for 0, 4, and 7 g/day, respectively), NDF (59.4, 63.9, and 62.4%), and hemicellulose (HC; 56.2, 63.6, and 65.9%) compared with rams fed 0 g/day, while CP digestibility (46.4, 49.9, and 57.8%) was improved (P < 0.05) in rams fed 7 g/day compared with those fed 0 and 4 g/day. Rams fed 4 g/day EO digested greater (P < 0.05) HC (64.1, 71.4, and 69.1%) than rams fed 0 g/day, while rams fed 7 g/day were intermediate and similar (P > 0.10). Rams fed the EOC combination at 4 and 7 g/day demonstrated greater (P < 0.05) digestibilities of DM (57.7, 60.0, and 60.0%), NDF (21.4, 28.8, and 27.7%), and ADF (24.3, 33.3, and 34.4%) than rams fed 0 g/day. The SEM and SM techniques visually demonstrated minor evidence of husk and leaf digestibility in rams across the three experiments when fed 0 g/day of Co, EO, or EOC; rams fed 4 g/day of Co, EO, or EOC exhibited varying visual signs of leaf digestion with some palisade tissue, spongy tissue, and whole vein structure remaining, while in rams fed 7 g/day, only the vein structure remained. Results demonstrated that feeding Co, EO, or EOC at 4 or 7 g/day enhanced ruminal nutrient digestion and fermentation parameters, which was visually confirmed via SEM and SM.

Download Full-text

Flavored Olive Oil as a Preservation Means of Reduced Salt Spanish Style Green Table Olives (cv. Chalkidiki)

Foods ◽

10.3390/foods10020392 ◽

2021 ◽

Vol 10 (2) ◽

pp. 392

Author(s):

Maria Papapostolou ◽

Fani T. Mantzouridou ◽

Maria Z. Tsimidou

Keyword(s):

Essential Oil ◽

Essential Oils ◽

Olive Oil ◽

Population Control ◽

Microbiological Quality ◽

Table Olives ◽

Lemon Balm ◽

Oregano Essential Oil ◽

Microbiological Parameters ◽

Reduced Salt

Reformulation of products fermented in brine is a challenging area of research. Continuing the efforts toward the establishment of table olives as a healthy food for all population groups, this study aimed at examining whether olive oil flavored with essential oils can be used as a preservation means for reduced salt Spanish style green table olives (cv. Chalkidiki). Response surface methodology was applied to organize experimentation and assess data. As independent factors, concentrations of the essential oils used (oregano, lemon balm and bay laurel) and time of storage under vacuum were set. Microbiological parameters (pathogens and fermentation-related microbes), color and firmness attributes were used as responses. Models indicated that each essential oil exerted a preservative role to maintain microbiological quality of reduced salt table olives. Concurrently, appearance attributes of the latter were retained at desirable values. Oregano essential oil had a profound role against pathogens. Lemon balm and bay laurel essential oils were found to be important for yeast population control. The results are promising toward the use of flavored olive oil as a preservation means for tailor-made reduced salt table olives, a practice that may enhance local industry innovative activity in a practical and effective way.

Download Full-text