Monitoring Changes in Biochemical and Metabolite Profiles in Garlic Cloves during Storage.

Storage is important for the garlic cloves industry because it is critical to enabling a year-round supply. This study aimed to investigate the changes in biochemical and metabolic profiles in garlic cloves in terms of different temperatures and cultivars during storage using nontargeted and targeted metabolomics. The results showed that the storage temperatures and times were important factors affecting the composition and metabolite content of garlic cloves. In detail, the metabolic profiling of garlic cloves changed significantly at 22 °C, which was mainly related to sprouting. Furthermore, γ-glutamyl peptide was converted into the corresponding flavor precursors or free amino acids, leading to the fluctuation in the amount of nutrients in garlic cloves. In contrast, the quality of garlic cloves remained stable for 290 days at 0 °C though metabolism still occurred, which indicated that the slight chemical changes did not impact the quality significantly and low temperature could prolong their dormancy.

Whole-genome sequencing of four culturable endophytic bacteria from German hardneck garlic cloves (Allium sativum L.).

We present the whole-genome sequence of four bacterial endophytes associated with German hardneck garlic cloves (Allium sativum L.). Among them, Agrobacterium fabrum and Pantoea agglomerans are associated with plant protection, while Rahnella perminowiae and Stenotrophomonas lactitubi are pathogens. These data will facilitate the identification of genes to improve garlic.

Comparison of two extraction methods (high pressure extraction vs. maceration) for the total and relative amount of hydrophilic and lipophilic organosulfur compounds in garlic cloves and stems. An application to the Italian ecotype "Aglio Rosso di Sulmona" (Sulmona Red Garlic).

Garlic-based extracts have been surveyed as healthy promoting supplements in relation to their content of organosulfur compounds. The present study investigated the effect of high pressure extraction and maceration, and four extraction solvents (three hydroalcoholic mixtures and sunflower oil) on the total and relative amounts of the main organosulfur compounds of clove and stem extracts of the Italian ecotype "Aglio Rosso di Sulmona" (Sulmona Red Garlic). Organosulfur compounds were more abundant in cloves than in stem extracts. High pressure extraction led to higher recoveries of hydrophilic compounds than maceration whereas the highest amounts of lipophilic compounds were detected in macerates. A higher alliin-to-allicin conversion ratio was detected in clove, in comparison to stem extracts. Sunflower oil fostered allicin decay to compounds such as ajoenes, vinyldithiins and sulfides. The use of specific extraction methods may lead to standardised grade extracts, both from native raw materials and by-products.

Influence of packaging materials on postharvest physiology and texture of garlic cloves during refrigeration storage.

This study aims to investigate the postharvest physiology and texture of garlic cloves packaged in polyethylene terephthalate (PET), polyethylene (PE), aluminized kraft paper (AKP), single kraft paper (SKP), and mesh bag. Germination rate, electrical conductivity, respiration intensity, water content, and texture were determined during 180 d storage at -2 °C. Results showed that the germination of garlic cloves packaged in PET, PE, and AKP was effectively inhibited during storage. PE effectively reduced the degree of damage to the cell membranes of the garlic cloves. PE and SKP significantly inhibited respiratory intensity during storage. Garlic cloves water content did not change significantly in 90 d storage which packaged in PE and SKP. PE exhibited better effect on the texture and freshness of garlic cloves than the other materials. In conclusion, PE is the best packaging material for maintaining the quality attributes and extending the shelf lives of garlic cloves.

Evolution of some physicochemical and antioxidant properties of black garlic whole bulbs and peeled cloves.

Black garlic was processed at three different temperatures of heat treatment (72°, 75° and 78°C) and close to 90% of relative humidity. Two types of material source were used: whole bulbs and peeled cloves. Total soluble solids content (°Brix), pH, water activity (aw), browning intensive (L value), total polyphenol content, antioxidant capacity and total polyphenol index of the raw and heated garlic were determined. This study showed the changes occurring in the physicochemical and antioxidant properties of the garlic during the heat-treatment evolution. The soluble solids content (°Brix) in garlic increased gradually and the pH decreased in whole bulbs and peeled garlics. The polyphenol content measured by the Folin-Ciocalteu method showed a significant increase during the heat-treatment in all the cases. Also, the antioxidant capacity measured by the ABTS radical increased significantly during the heat-treatment.