Aldia Katherinatama

Natural antioxidants are widely valued for their bioavailability and potential health benefits. Coffee (Coffea spp.) is recognised as a rich source of bioactive compounds, not only in its beans but also in its leaves and fruit tissues. In Indonesia, coffee leaves have long been utilised to prepare a traditional beverage known as Aia kawa, which is believed to possess notable antioxidant properties. This study evaluated the relative water content (RWC), total phenolic content (TPC), total flavonoid content (TFC), total tannin content (TTC), and total antioxidant activity of coffee leaves at different stages of leaf and tree maturity. The results demonstrated that young leaves harvested from young coffee trees exhibited the highest TPC (3.2 mg GAE/g), TFC (18.5 mg QE/g) and antioxidant activity (0.54 mg AAE/g; p < 0.05). No significant differences in phenolic content were observed between mature leaves from young trees and young leaves from mature trees. Tannin values were clarified and expressed as micrograms tannic acid equivalent per gram dry sample (725-1100 µg TAE/g), avoiding misinterpretation of the unit as mg/g. A positive association was observed between phenolic content and antioxidant activity, with a strong relationship for TPC (R² = 0.981) and a moderate relationship for TFC (R² = 0.855). These findings indicate that coffee leaves, particularly young leaves from young trees, represent a promising and under utilised source of natural antioxidants with potential applications in functional foods and nutraceutical products.

The volatile profiles of palm sugar, a traditional sweetener used in Southeast Asia, vary according to its geographic and botanical origin. This study investigated the volatile organic components (VOCs) of Indonesian and Malaysian palm sugars derived from Arenga pinnata, Nypa fruticans, and Cocos nucifera using solid-phase microextraction-GC-MS and MS-e-nose analyses. A total of 42 compounds were detected, including 12 Maillard reaction products, 10 esters, 8 alcohols, 5 ketones, 3 carboxylic acids, 3 phenols, and 1 aldehyde. The Indonesian palm (West Java) and nipa (Central Java) sugars contained VOCs of 39.45 and 38.49 µg/100 g palm sugar, respectively, whereas the Balinese palm and Malaysian coconut sugars contained significantly lower volatiles (18.56 and 11.41 µg/100 g, respectively). Hierarchical clustering and principal component analysis (PCA) revealed diverse composition profiles, with palm-derived sugars rich in pyrazines, nipa sugars dominated by carboxylic acids, and coconut sugars characterized by alcohols such as [R,R]-2,3-butanediol. PCA of the MS-e-nose analysis confirmed these variations, with PAR scaling enhancing their differentiation and providing valuable loading plots, including ion masses m/z 43 and 45 (hydrocarbons or carboxylic acids), m/z 60 (acetic acid), and m/z 108 (dimethyl-pyrazines). These findings highlight the influence of geography and plant origin on palm sugar VOCs, which may affect their sensory attributes.

Citrus-flavored vegetable oils (CFVO) demand has grown rapidly in the food industry due to increasing consumer demand for salads as a healthy food choice. Salad dressing has a distinctive taste from sour-tasting citrus that when added to salads to increase acceptance. This study primarily aimed to characterize antioxidant activity, total flavonoid content, and sensory quality by hedonic and organoleptic test between all unflavored oil and CFVO from three different vegetable oils (coconut oil (Cocos nucifera L.), palm oil (Elaeis guineensis L.), sesame oil (Sesamum indicum L.)) and three citruses (key lime (Citrus aurantifolia), kaffir lime (Citrus hystrix), and nasnaran (Citrus ambylcarpa)). One-Way ANOVA with post hoc Tukey were conducted to assess antioxidant and flavonoid differences. ANOVA with Tukey HSD and HSD, PCA and HCA, and a Spearman correlation analysis were conducted to assess the sensory qualities of citrus-flavored vegetable oils. There were different hedonic responses towards citruses in addition to the vegetable oils for each hedonic attribute. There is also a different response to the antioxidant and total flavonoids content of each treatment. The best formula according the multi-attribute decision using a compensatory model and additive weighting technique (MADCAW) score describes key lime (140%) flavored coconut oil as the best formula as having 56.58% antioxidant, 37.00 mg QE/100 g flavonoid and color liking 1.84, aroma liking 3.56, and taste liking 1.88. In conclusion, citrus-flavored vegetable oil has the potential to be a high-antioxidant vegetable oil with good acceptance by consumers.

Shiikuwasha, a citrus fruit native to Okinawa, Japan, has various cultivation lines with distinct free volatile and non-volatile components. However, the glycosylated volatiles, which are sources of hidden aromas, remain unknown. This study aimed to characterize the chemical profiles of free and glycosidically bound volatile as well as non-volatile components in the mature fruits of six Shiikuwasha cultivation lines: Ishikunibu, Izumi kugani-like, Kaachi, Kohama, Nakamoto seedless, and Ogimi kugani. Free volatiles were analyzed using solid-phase microextraction–gas chromatography–mass spectrometry. Glycosides were collected via solid-phase extraction and hydrolyzed with β-glucosidase, and the released volatiles were measured. Additionally, the non-volatile components were determined using non-targeted proton nuclear magnetic resonance analysis. Total free and bound volatiles ranged from 457 to 8401 µg/L and from 104 to 548 µg/L, respectively, and the predominant free volatiles found were limonene, γ-terpinene, and p-cymene. Twenty volatiles were released from glycosides, including predominant 1-hexanol and benzyl alcohol, with Kaachi and Ogimi kugani showing higher concentrations. Principal component analysis (PCA) revealed that taste-related compounds like sucrose, citrate, and malate influenced line differentiation. The PCA of the combined data of free and bound volatile and non-volatile components showed flavor component variances across all lines. These findings provide valuable insights into the chemical profiles of Shiikuwasha fruits for fresh consumption and food and beverage processing.

Fortification of oatmeal cookies with ingredients that are physically more attractive and functional is an interesting breakthrough for improving oatmeal cookies to be a favourite healthy food. Green tea was considered to be a food fortification because of its phytochemical content, which is beneficial to health. This study was aimed at getting more insight into the effect of green tea powder (GTP) fortification on physical (texture and colour), chemical (moisture, fat, ash, protein, carbohydrates, crude fibre content, and calories) and hedonic characteristics of oatmeal cookies. The treatments in this study were 5 levels of GTP fortification (each repeated 4 times) i.e., 0, 2, 4, 6, and 8% into the cookie’s dough. There was a significant effect (p≤0.05) of GTP fortification on the texture, colour, ash, fat, crude fibre, and total calorie products. The 2% GTP fortification in oatmeal cookies was the most preferred by the panellists, because the higher percentages of GTP affected the more bitter taste and harder texture. Fortification of oatmeal cookies with 6% GTP produces the final product, namely green tea oatmeal cookies (GTOC), which are low in fat and carbohydrates but high in fibre and protein content. GTP fortification can improve the oatmeal cookie's functional properties