Evaluation of Pretreatments and Extraction Conditions on the Antifungal and Antioxidant Effects of Garlic (Allium sativum) Peel Extracts.

This study aimed to evaluate the effect of pretreatments and extraction conditions on the antioxidant and antifungal characteristics of garlic peel extracts. The effect of pretreatments (fermentation and steam cooking) on the yield, antifungal (Colletotrichum gloeosporioides and Botrytis cinerea), and antioxidant (total phenolic compounds, total flavonoids, and antioxidant capacity) properties of garlic peel extracts were evaluated. A selected pretreatment was applied to evaluate the extraction conditions (solvent, solvent concentration, temperature, and time) on the antifungal activity of garlic peel extracts. At last, garlic peel extracts obtained under specific conditions was applied to papaya and strawberry fruits as preventive and curative treatments against Colletotrichum gloeosporioides and Botrytis cinerea, respectively. Steam cooking pretreatment significantly increased the antifungal and antioxidant capacities of garlic peel extracts compared to the fermentation process. Garlic peel extracts obtained with methanol (60%) for 18 h (25 °C) showed the highest antifungal activity against both microorganisms assessed (57.57% and 75.76% for B. cinerea and C. gloeosporioides, respectively,) on in vitro assays. Moreover, in vivo results indicated that preventive treatment significantly reduced rot disease in papaya (88.95%) and strawberry (54.13%) fruits. Although more studies about the antifungal mechanisms of garlic peel extracts are needed, these results indicated that garlic peel extracts could be used as an antifungal agent.

Identification of anthocyanic profile and determination of antioxidant activity of Dahlia pinnata petals: A potential source of anthocyanins.

In recent decades, the food industry has focused on the search for potential sources of anthocyanins that are able to provide color to replace synthetic dyes and at the same time provide health benefits through food products. Thus, in the present work, we propose the Dahlia pinnata flower as a potential source of anthocyanins. The dahlia is a native, annual flower from Mexico with a wide diversity of shapes and colors. The ancestral use of the flower in several dishes, its abundance, and the intense color of the flowers known as black make the D. pinnata flower a suitable candidate to be considered as a potential source of anthocyanins. Thus, the aim of this research is the determination of its nutritional composition, anthocyanin profile, and antioxidant activity. For this purpose, proximate composition of petals was determined by the AOAC standard methods. Anthocyanins were extracted from the dried petals of the flower with 0.1% HCl in methanol and 70% aqueous acetone solution and purified through Amberlite-XAD7-HP resin. Then, the purified extracts were analyzed for antioxidant activity by the DPPH method and the anthocyanin profile was characterized by HPLC and UPLC-MS/MS. Results showed that D. pinnata flowers have a proximate composition similar to other important edible flowers with a high level of moisture (87%-92%) and fiber (6%-7%). The antioxidant activity of both purified extracts was considerable (2.6-12 g/ml) compared to other sources of anthocyanins. The anthocyanin profile of the purified extracts contains four main anthocyanins: delphinidin-3-glucoside, delphinidin-3-rutinoside, pelargonidin-3-sambubioside-5-glucoside, and peonidin-3-sambubioside-5-glucoside, the last two being uncommon as major anthocyanin components in other plant sources. PRACTICAL APPLICATION: We present a potential and novel source of anthocyanins based on anthocyanin content and antioxidant activity of Dahlia pinnata petals. On the basis of UPLC-MS/MS studies, we identified four main anthocyanins, so this information provides the opportunity to study the source in many areas such as natural pigment stabilization, food additives, and antioxidants.

Effect of Goat and Cow Milk Ratios on the Physicochemical, Rheological, and Sensory Properties of a Fresh Panela Cheese.

Fresh cheeses, Panela type, were manufactured from cow milk and with goat milk incorporation, constituting 4 blends of milks (G10:C90, G20:C80, G30:C70, G40:C60, v/v). The cheeses were analyzed to determine the effect of the different goat milk ratios on the physicochemical, textural, rheological, and sensory properties over 15 d of storage. Significant differences in protein (14.6% to 18.5%), fat (13.0% to 19.4%), and moisture contents (51.7% to 61.3%), pH (6.38 to 6.67), color (Lh  > 64.4, ah  > 1.06, bh  > 5.14), textural (σf  > 14.8 kPa, εC : 0.77 to 0.79, elasticity modulus > 13.5 kPa), and rheological parameters (G' > G'', G': 10.6 to 31.9 kPa, G'': 2.39 to 7.31 kPa, tan δ: 0.21 to 0.24) were detected as a function of the milks ratio, as well as a function of the storage time. The incorporation of goat milk improved the overall quality in the formulation of Panela cheese, enhancing the texture, flavor and aroma, commonly associated with hand-crafted cheeses when they are used in the proper ratio. Furthermore, the nutritional value of the cheese is increased with the incorporation of goat milk, which can contribute to a better consumer health.