This study aims to determine the botanical composition of different pastures in a semiarid region of Algeria and investigate the aromatic profile of the characteristic plant species grazed by goats and sheep. At three pastures (1: montane area with spontaneous vegetation ‘never cultivated before’, 2: previously cultivated but set at rest, 3: cultivated, under cereal production), plants were sampled twice during April–May to determine plant composition. Based on dominance of fresh aerial biomass of each plant per pasture and consumption by dairy goats, 10 species (Atractylis humilis, Calendula arvensis, Filago pygmaea, Globularia alypum, Hordeum vulgare, Malva sylvestris, Plantago sp., Scolymus hispanicus, Sonchus asper and Thymus algeriensis) were selected and sampled once at flowering stage to characterize their aromatic profile. The odour-active compounds (OACs) of the selected species were extracted using steam distillation, then detected and identified using gas chromatography/mass spectrometry/olfactometry (GC/MS/O). The analysis of botanical composition revealed the presence of 70 species (29 in mountain, 40 in set at rest, 11 in cultivated pasture) belonging to 62 genera and 22 families, with dominance of Asteraceae species. A total of 86 different OACs were identified, including mainly terpenes (21) and aldehydes (18). Among the OACs, 19 different compounds have various odour notes including herbaceous, floral, sweet spicy, fried, mint, cooked, fruity, sulphur, sweet and unpleasant notes. The number of OACs and individual chemical classes differed significantly between selected species. Atractylis humilis contained more OACs than Scolymus hispanicus and Plantago sp., whereas Globularia alypum had higher number of OACs compared to Plantago sp. This study gave a general overview on plant aroma profile of semiarid pastures in Algeria and suggests that the aromatic profile of grazed plants in the pasture is determinant of the aromatic quality of dairy-derived foods which depends also on animal feed selection.

中文翻译：

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阿尔及利亚半干旱牧场的植物成分和香气成分

本研究旨在确定阿尔及利亚半干旱地区不同牧场的植物成分，并调查山羊和绵羊放牧的特征植物物种的芳香特征。在三个牧场（1：具有“以前从未种植过”的自发植被的山地地区，2：以前种植过但处于静止状态，3：种植，在谷物生产中），在 4 月至 5 月期间对植物进行了两次采样以确定植物组成。基于由奶山羊每牧草和消费各植物的鲜生物量的空中的主导地位，10种（苍术蒿草，金盏花，菲拉戈矮，Globularia alypum，大麦，芘，车前草、Scolymus hispanicus、Sonchus asper和Thymus algeriensis) 在开花期被选择和采样一次，以表征它们的芳香特征。所选物种的气味活性化合物 (OAC) 使用蒸汽蒸馏进行提取，然后使用气相色谱/质谱/嗅觉分析 (GC/MS/O) 进行检测和鉴定。植物组成分析显示，有70种（山地29种，静养40种，栽培牧草11种），隶属于62属22科，以菊科植物为主。共鉴定出 86 种不同的 OAC，主要包括萜烯 (21) 和醛 (18)。在 OAC 中，19 种不同的化合物具有不同的气味，包括草本、花香、甜辣、油炸、薄荷、煮熟、果味、硫磺、甜味和令人不快的气味。苍术蒿草包含超过OACS蓟hispanicus和车前子属，而Globularia alypum有较高的数量相比，OACS的车前子SP。本研究对阿尔及利亚半干旱牧场的植物香气特征进行了总体概述，并表明牧场中放牧植物的芳香特征决定了乳制品的芳香品质，这也取决于动物饲料的选择。